National Library of Energy BETA

Sample records for wave cloud radar

  1. Millimeter Wave Cloud Radar (MMCR) Handbook

    SciTech Connect (OSTI)

    KB Widener; K Johnson

    2005-01-30

    The millimeter cloud radar (MMCR) systems probe the extent and composition of clouds at millimeter wavelengths. The MMCR is a zenith-pointing radar that operates at a frequency of 35 GHz. The main purpose of this radar is to determine cloud boundaries (e.g., cloud bottoms and tops). This radar will also report radar reflectivity (dBZ) of the atmosphere up to 20 km. The radar possesses a doppler capability that will allow the measurement of cloud constituent vertical velocities.

  2. ARM: Millimeter Wave Cloud Radar (MMCR), replaces mmcrcal and mmcrmoments datastreams following C-40 processor upgrade of 2003.09.09

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Karen Johnson; Nitin Bharadwaj

    1990-01-01

    Millimeter Wave Cloud Radar (MMCR), replaces mmcrcal and mmcrmoments datastreams following C-40 processor upgrade of 2003.09.09

  3. The Status of the ACRF Millimeter Wave Cloud Radars (MMCRs), the Path Forward for Future MMCR Upgrades, the Concept of 3D Volume Imaging Radar and the UAV Radar

    SciTech Connect (OSTI)

    P Kollias; MA Miller; KB Widener; RT Marchand; TP Ackerman

    2005-12-30

    The United States (U.S.) Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) operates millimeter wavelength cloud radars (MMCRs) in several climatological regimes. The MMCRs, are the primary observing tool for quantifying the properties of nearly all radiatively important clouds over the ACRF sites. The first MMCR was installed at the ACRF Southern Great Plains (SGP) site nine years ago and its original design can be traced to the early 90s. Since then, several MMCRs have been deployed at the ACRF sites, while no significant hardware upgrades have been performed. Recently, a two-stage upgrade (first C-40 Digital Signal Processors [DSP]-based, and later the PC-Integrated Radar AcQuisition System [PIRAQ-III] digital receiver) of the MMCR signal-processing units was completed. Our future MMCR related goals are: 1) to have a cloud radar system that continues to have high reliability and uptime and 2) to suggest potential improvements that will address increased sensitivity needs, superior sampling and low cost maintenance of the MMCRs. The Traveling Wave Tube (TWT) technology, the frequency (35-GHz), the radio frequency (RF) layout, antenna, the calibration and radar control procedure and the environmental enclosure of the MMCR remain assets for our ability to detect the profile of hydrometeors at all heights in the troposphere at the ACRF sites.

  4. Scanning ARM Cloud Radar Handbook

    SciTech Connect (OSTI)

    Widener, K; Bharadwaj, N; Johnson, K

    2012-06-18

    The scanning ARM cloud radar (SACR) is a polarimetric Doppler radar consisting of three different radar designs based on operating frequency. These are designated as follows: (1) X-band SACR (X-SACR); (2) Ka-band SACR (Ka-SACR); and (3) W-band SACR (W-SACR). There are two SACRs on a single pedestal at each site where SACRs are deployed. The selection of the operating frequencies at each deployed site is predominantly determined by atmospheric attenuation at the site. Because RF attenuation increases with atmospheric water vapor content, ARM's Tropical Western Pacific (TWP) sites use the X-/Ka-band frequency pair. The Southern Great Plains (SGP) and North Slope of Alaska (NSA) sites field the Ka-/W-band frequency pair. One ARM Mobile Facility (AMF1) has a Ka/W-SACR and the other (AMF2) has a X/Ka-SACR.

  5. ARM - Field Campaign - Cloud Radar IOP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govCampaignsCloud Radar IOP ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Cloud Radar IOP 1997.04.02 - 1997.04.22 Lead Scientist : Brooks Martner Data Availability MMCR Quick Look Data For data sets, see below. Abstract The objectives of the Cloud Radar IOP are to: support the calibration of the ARM millimeter cloud radar and evaluate the spatial versus temporal variability of cloud properties as seen

  6. First observations of tracking clouds using scanning ARM cloud radars

    SciTech Connect (OSTI)

    Borque, Paloma; Giangrande, Scott; Kollias, Pavlos

    2014-12-01

    Tracking clouds using scanning cloud radars can help to document the temporal evolution of cloud properties well before large drop formation (first echo). These measurements complement cloud and precipitation tracking using geostationary satellites and weather radars. Here, two-dimensional (2-D) Along-Wind Range Height Indicator (AW-RHI) observations of a population of shallow cumuli (with and without precipitation) from the 35-GHz scanning ARM cloud radar (SACR) at the DOE Atmospheric Radiation Measurements (ARM) program Southern Great Plains (SGP) site are presented. Observations from the ARM SGP network of scanning precipitation radars are used to provide the larger scale context of the cloud field and to highlight the advantages of the SACR to detect the numerous, small, non-precipitating cloud elements. A new Cloud Identification and Tracking Algorithm (CITA) is developed to track cloud elements. In CITA, a cloud element is identified as a region having a contiguous set of pixels exceeding a preset reflectivity and size threshold. The high temporal resolution of the SACR 2-D observations (30 sec) allows for an area superposition criteria algorithm to match cloud elements at consecutive times. Following CITA, the temporal evolution of cloud element properties (number, size, and maximum reflectivity) is presented. The vast majority of the designated elements during this cumulus event were short-lived non-precipitating clouds having an apparent life cycle shorter than 15 minutes. The advantages and disadvantages of cloud tracking using an SACR are discussed.

  7. First observations of tracking clouds using scanning ARM cloud radars

    SciTech Connect (OSTI)

    Borque, Paloma; Giangrande, Scott; Kollias, Pavlos

    2014-12-01

    Tracking clouds using scanning cloud radars can help to document the temporal evolution of cloud properties well before large drop formation (‘‘first echo’’). These measurements complement cloud and precipitation tracking using geostationary satellites and weather radars. Here, two-dimensional (2-D) Along-Wind Range Height Indicator (AW-RHI) observations of a population of shallow cumuli (with and without precipitation) from the 35-GHz scanning ARM cloud radar (SACR) at the DOE Atmospheric Radiation Measurements (ARM) program Southern Great Plains (SGP) site are presented. Observations from the ARM SGP network of scanning precipitation radars are used to provide the larger scale context of the cloud field and to highlight the advantages of the SACR to detect the numerous, small, non-precipitating cloud elements. A new Cloud Identification and Tracking Algorithm (CITA) is developed to track cloud elements. In CITA, a cloud element is identified as a region having a contiguous set of pixels exceeding a preset reflectivity and size threshold. The high temporal resolution of the SACR 2-D observations (30 sec) allows for an area superposition criteria algorithm to match cloud elements at consecutive times. Following CITA, the temporal evolution of cloud element properties (number, size, and maximum reflectivity) is presented. The vast majority of the designated elements during this cumulus event were short-lived non-precipitating clouds having an apparent life cycle shorter than 15 minutes. The advantages and disadvantages of cloud tracking using an SACR are discussed.

  8. First observations of tracking clouds using scanning ARM cloud radars

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Borque, Paloma; Giangrande, Scott; Kollias, Pavlos

    2014-12-01

    Tracking clouds using scanning cloud radars can help to document the temporal evolution of cloud properties well before large drop formation (‘‘first echo’’). These measurements complement cloud and precipitation tracking using geostationary satellites and weather radars. Here, two-dimensional (2-D) Along-Wind Range Height Indicator (AW-RHI) observations of a population of shallow cumuli (with and without precipitation) from the 35-GHz scanning ARM cloud radar (SACR) at the DOE Atmospheric Radiation Measurements (ARM) program Southern Great Plains (SGP) site are presented. Observations from the ARM SGP network of scanning precipitation radars are used to provide the larger scale context of the cloud fieldmore » and to highlight the advantages of the SACR to detect the numerous, small, non-precipitating cloud elements. A new Cloud Identification and Tracking Algorithm (CITA) is developed to track cloud elements. In CITA, a cloud element is identified as a region having a contiguous set of pixels exceeding a preset reflectivity and size threshold. The high temporal resolution of the SACR 2-D observations (30 sec) allows for an area superposition criteria algorithm to match cloud elements at consecutive times. Following CITA, the temporal evolution of cloud element properties (number, size, and maximum reflectivity) is presented. The vast majority of the designated elements during this cumulus event were short-lived non-precipitating clouds having an apparent life cycle shorter than 15 minutes. The advantages and disadvantages of cloud tracking using an SACR are discussed.« less

  9. ARM - Field Campaign - DC-8 Cloud Radar Campaign

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govCampaignsDC-8 Cloud Radar Campaign Comments? We would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : DC-8 Cloud Radar Campaign...

  10. CloudSat as a Global Radar Calibrator

    SciTech Connect (OSTI)

    Protat, Alain; Bouniol, Dominique; O'Connor, E. J.; Baltink, Henk K.; Verlinde, J.; Widener, Kevin B.

    2011-03-01

    The calibration of the CloudSat spaceborne cloud radar has been thoroughly assessed using very accurate internal link budgets before launch, comparisons with predicted ocean surface backscatter at 94 GHz, direct comparisons with airborne cloud radars, and statistical comparisons with ground-based cloud radars at different locations of the world. It is believed that the calibration of CloudSat is accurate to within 0.5 to 1 dB. In the present paper it is shown that an approach similar to that used for the statistical comparisons with ground-based radars can now be adopted the other way around to calibrate other ground-based or airborne radars against CloudSat and / or detect anomalies in long time series of ground-based radar measurements, provided that the calibration of CloudSat is followed up closely (which is the case). The power of using CloudSat as a Global Radar Calibrator is demonstrated using the Atmospheric Radiation Measurement cloud radar data taken at Barrow, Alaska, the cloud radar data from the Cabauw site, The Netherlands, and airborne Doppler cloud radar measurements taken along the CloudSat track in the Arctic by the RASTA (Radar SysTem Airborne) cloud radar installed in the French ATR-42 aircraft for the first time. It is found that the Barrow radar data in 2008 are calibrated too high by 9.8 dB, while the Cabauw radar data in 2008 are calibrated too low by 8.0 dB. The calibration of the RASTA airborne cloud radar using direct comparisons with CloudSat agrees well with the expected gains and losses due to the change in configuration which required verification of the RASTA calibration.

  11. ARM - Evaluation Product - Scanning ARM Cloud Radar Corrections (SACRCOR)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ProductsScanning ARM Cloud Radar Corrections (SACRCOR) ARM Data Discovery Browse Data Documentation Use the Data File Inventory tool to view data availability at the file level. Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Evaluation Product : Scanning ARM Cloud Radar Corrections (SACRCOR) [ ARM research - evaluation data product ] This dataset contains moments from the Scanning ARM Cloud Radars (SACRs) which have been filtered and corrected

  12. Mixed-Phase Cloud Retrievals Using Doppler Radar Spectra

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Mixed-Phase Cloud Retrievals Using Doppler Radar Spectra M. D. Shupe, S. Y. Matrosov, and T. L. Schneider National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado P. Kollias Rosentiel School of Marine Atmospheric Sciences University of Miami Miami, Florida Introduction The radar Doppler spectrum contains a wealth of information on cloud microphysical properties. Typically, radar-based cloud retrievals use only the zeroth or first moments of the

  13. W-band ARM Cloud Radar (WACR) Handbook

    SciTech Connect (OSTI)

    Widener, KB; Johnson, K

    2005-01-05

    The W-band Atmospheric Radiation Measurement (ARM) Program Cloud Radar (WACR) systems are zenith pointing Doppler radars that probe the extent and composition of clouds at 95.04 GHz. The main purpose of this radar is to determine cloud boundaries (e.g., cloud bottoms and tops). This radar reports estimates for the first three spectra moments for each range gate up to 15 km. The 0th moment is reflectivity, the 1st moment is radial velocity, and the 2nd moment is spectral width. Also available are the raw spectra files. Unlike the millimeter wavelength cloud radar (MMCR), the WACR does not use pulse coding and operates in only copolarization and cross-polarization modes.

  14. Cloud radar Doppler spectra in drizzling stratiform clouds: 1. Forward modeling and remote sensing applications

    SciTech Connect (OSTI)

    Kollias, P.; Luke, E.; Rmillard, J.; Szyrmer, W.

    2011-07-02

    Several aspects of spectral broadening and drizzle growth in shallow liquid clouds remain not well understood. Detailed, cloud-scale observations of microphysics and dynamics are essential to guide and evaluate corresponding modeling efforts. Profiling, millimeter-wavelength (cloud) radars can provide such observations. In particular, the first three moments of the recorded cloud radar Doppler spectra, the radar reflectivity, mean Doppler velocity, and spectrum width, are often used to retrieve cloud microphysical and dynamical properties. Such retrievals are subject to errors introduced by the assumptions made in the inversion process. Here, we introduce two additional morphological parameters of the radar Doppler spectrum, the skewness and kurtosis, in an effort to reduce the retrieval uncertainties. A forward model that emulates observed radar Doppler spectra is constructed and used to investigate these relationships. General, analytical relationships that relate the five radar observables to cloud and drizzle microphysical parameters and cloud turbulence are presented. The relationships are valid for cloud-only, cloud mixed with drizzle, and drizzle-only particles in the radar sampling volume and provide a seamless link between observations and cloud microphysics and dynamics. The sensitivity of the five observed parameters to the radar operational parameters such as signal-to-noise ratio and Doppler spectra velocity resolution are presented. The predicted values of the five observed radar parameters agree well with the output of the forward model. The novel use of the skewness of the radar Doppler spectrum as an early qualitative predictor of drizzle onset in clouds is introduced. It is found that skewness is a parameter very sensitive to early drizzle generation. In addition, the significance of the five parameters of the cloud radar Doppler spectrum for constraining drizzle microphysical retrievals is discussed.

  15. Scanning ARM Cloud Radars Part I: Operational Sampling Strategies

    SciTech Connect (OSTI)

    Kollias, Pavlos; Bharadwaj, Nitin; Widener, Kevin B.; Jo, Ieng; Johnson, Karen

    2014-03-01

    Probing clouds in three-dimensions has never been done with scanning millimeter-wavelength (cloud) radars in a continuous operating environment. The acquisition of scanning cloud radars by the Atmospheric Radiation Measurement (ARM) program and research institutions around the world generate the need for developing operational scan strategies for cloud radars. Here, the first generation of sampling strategies for the Scanning ARM Cloud Radars (SACRs) is discussed. These scan strategies are designed to address the scientific objectives of the ARM program, however, they introduce an initial framework for operational scanning cloud radars. While the weather community uses scan strategies that are based on a sequence of scans at constant elevations, the SACRs scan strategies are based on a sequence of scans at constant azimuth. This is attributed to the cloud properties that are vastly different for rain and snow shafts that are the primary target of precipitation radars. A cloud surveillance scan strategy is introduced (HS-RHI) based on a sequence of horizon-to-horizon Range Height Indicator (RHI) scans that sample the hemispherical sky (HS). The HS-RHI scan strategy is repeated every 30 min to provide a static view of the cloud conditions around the SACR location. Between HS-RHI scan strategies other scan strategies are introduced depending on the cloud conditions. The SACRs are pointing vertically in the case of measurable precipitation at the ground. The radar reflectivities are corrected for water vapor attenuation and non-meteorological detection are removed. A hydrometeor detection mask is introduced based on the difference of cloud and noise statistics is discussed.

  16. An Improved Cloud Classification Algorithm Based on the SGP CART...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in the world. The millimeter wave cloud radar (MMCR) provides radar reflectivity and mean Doppler velocity profiles for most of clouds in the troposphere. Raman lidar provide not...

  17. Posters Radar/Radiometer Retrievals of Cloud Liquid Water and

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    1 Posters Radar/Radiometer Retrievals of Cloud Liquid Water and Drizzle: Analysis Using Data from a Three-Dimensional Large Eddy Simulation of Marine Stratocumulus Clouds G. Feingold Cooperative Institute for Research in Environmental Sciences University of Colorado Boulder, Colorado A. S. Frisch National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado B. Stevens and W. R. Cotton Colorado State University Fort Collins, Colorado Introduction Marine

  18. Cloud radar Doppler spectra in drizzling stratiform clouds: 2. Observations and microphysical modeling of drizzle evolution

    SciTech Connect (OSTI)

    Kollias, P.; Luke, E.; Szyrmer, W.; Rmillard, J.

    2011-07-02

    In part I, the influence of cloud microphysics and dynamics on the shape of cloud radar Doppler spectra in warm stratiform clouds was discussed. The traditional analysis of radar Doppler moments was extended to include skewness and kurtosis as additional descriptors of the Doppler spectrum. Here, a short climatology of observed Doppler spectra moments as a function of the radar reflectivity at continental and maritime ARM sites is presented. The evolution of the Doppler spectra moments is consistent with the onset and growth of drizzle particles and can be used to assist modeling studies of drizzle onset and growth. Time-height radar observations are used to exhibit the coherency of the Doppler spectra shape parameters and demonstrate their potential to improve the interpretation and use of radar observations. In addition, a simplified microphysical approach to modeling the vertical evolution of the drizzle particle size distribution in warm stratiform clouds is described and used to analyze the observations. The formation rate of embryonic drizzle droplets due to the autoconversion process is not calculated explicitly; however, accretion and evaporation processes are explicitly modeled. The microphysical model is used as input to a radar Doppler spectrum forward model, and synthetic radar Doppler spectra moments are generated. Three areas of interest are studied in detail: early drizzle growth near the cloud top, growth by accretion of the well-developed drizzle, and drizzle depletion below the cloud base due to evaporation. The modeling results are in good agreement with the continental and maritime observations. This demonstrates that steady state one-dimensional explicit microphysical models coupled with a forward model and comprehensive radar Doppler spectra observations offer a powerful method to explore the vertical evolution of the drizzle particle size distribution.

  19. A Radar-based Observing System for Validation of Cloud Resolving Models

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Radar System Designed for Validation of Cloud Resolving Models Pavlos Kollias Atmospheric Science Division Brookhaven National Laboratory Cloud REsolving MOdel Radar (CREMORA) Scientific Justification Why do we need to know 3-D structure of cloud systems? Slide provided by Tom Ackerman -Evaluation of *Cloud System Resolving Models (one pathway to parameterization development and to climate models) *Satellite retrievals of cloud system properties -Lifecycle of convective systems - all phases of

  20. Interferometric millimeter wave and THz wave doppler radar

    DOE Patents [OSTI]

    Liao, Shaolin; Gopalsami, Nachappa; Bakhtiari, Sasan; Raptis, Apostolos C.; Elmer, Thomas

    2015-08-11

    A mixerless high frequency interferometric Doppler radar system and methods has been invented, numerically validated and experimentally tested. A continuous wave source, phase modulator (e.g., a continuously oscillating reference mirror) and intensity detector are utilized. The intensity detector measures the intensity of the combined reflected Doppler signal and the modulated reference beam. Rigorous mathematics formulas have been developed to extract bot amplitude and phase from the measured intensity signal. Software in Matlab has been developed and used to extract such amplitude and phase information from the experimental data. Both amplitude and phase are calculated and the Doppler frequency signature of the object is determined.

  1. Scanning Cloud Radar Observations at Azores: Preliminary 3D Cloud Products

    SciTech Connect (OSTI)

    Kollias, P.; Johnson, K.; Jo, I.; Tatarevic, A.; Giangrande, S.; Widener, K.; Bharadwaj, N.; Mead, J.

    2010-03-15

    The deployment of the Scanning W-Band ARM Cloud Radar (SWACR) during the AMF campaign at Azores signals the first deployment of an ARM Facility-owned scanning cloud radar and offers a prelude for the type of 3D cloud observations that ARM will have the capability to provide at all the ARM Climate Research Facility sites by the end of 2010. The primary objective of the deployment of Scanning ARM Cloud Radars (SACRs) at the ARM Facility sites is to map continuously (operationally) the 3D structure of clouds and shallow precipitation and to provide 3D microphysical and dynamical retrievals for cloud life cycle and cloud-scale process studies. This is a challenging task, never attempted before, and requires significant research and development efforts in order to understand the radar's capabilities and limitations. At the same time, we need to look beyond the radar meteorology aspects of the challenge and ensure that the hardware and software capabilities of the new systems are utilized for the development of 3D data products that address the scientific needs of the new Atmospheric System Research (ASR) program. The SWACR observations at Azores provide a first look at such observations and the challenges associated with their analysis and interpretation. The set of scan strategies applied during the SWACR deployment and their merit is discussed. The scan strategies were adjusted for the detection of marine stratocumulus and shallow cumulus that were frequently observed at the Azores deployment. Quality control procedures for the radar reflectivity and Doppler products are presented. Finally, preliminary 3D-Active Remote Sensing of Cloud Locations (3D-ARSCL) products on a regular grid will be presented, and the challenges associated with their development discussed. In addition to data from the Azores deployment, limited data from the follow-up deployment of the SWACR at the ARM SGP site will be presented. This effort provides a blueprint for the effort required for the development of 3D cloud products from all new SACRs that the program will deploy at all fixed and mobile sites by the end of 2010.

  2. Validation of a radar doppler spectra simulator using measurements from the ARM cloud radars

    SciTech Connect (OSTI)

    Remillard, J.; Luke, E.; Kollias, P.

    2010-03-15

    The use of forward models as an alternative approach to compare models with observations contains advantages and challenges. Radar Doppler spectra simulators are not new; their application in high- resolution models with bin microphysics schemes could help to compare model output with the Doppler spectra recorded from the vertically pointing cloud radars at the ARM Climate Research Facility sites. The input parameters to a Doppler spectra simulator are both microphysical (e.g., particle size, shape, phase, and number concentration) and dynamical (e.g., resolved wind components and sub-grid turbulent kinetic energy). Libraries for spherical and non-spherical particles are then used to compute the backscattering cross-section and fall velocities, while the turbulence is parameterized as a Gaussian function with a prescribed width. The Signal-to-Noise Ratio (SNR) is used to determine the amount of noise added throughout the spectrum, and the spectral smoothing due to spectral averages is included to reproduce the averaging realized by cloud radars on successive returns. Thus, realistic Doppler spectra are obtained, and several parameters that relate to the morphological characteristics of the synthetically generated spectra are computed. Here, the results are compared to the new ARM microARSCL data products in an attempt to validate the simulator. Drizzling data obtained at the SGP site by the MMCR and the AMF site at Azores using the WACR are used to ensure the liquid part and the turbulence representation part of the simulator are properly accounted in the forward model.

  3. Using Radar, Lidar, and Radiometer measurements to Classify Cloud Type and Study Middle-Level Cloud Properties

    SciTech Connect (OSTI)

    Wang, Zhien

    2010-06-29

    The project is mainly focused on the characterization of cloud macrophysical and microphysical properties, especially for mixed-phased clouds and middle level ice clouds by combining radar, lidar, and radiometer measurements available from the ACRF sites. First, an advanced mixed-phase cloud retrieval algorithm will be developed to cover all mixed-phase clouds observed at the ACRF NSA site. The algorithm will be applied to the ACRF NSA observations to generate a long-term arctic mixed-phase cloud product for model validations and arctic mixed-phase cloud processes studies. To improve the representation of arctic mixed-phase clouds in GCMs, an advanced understanding of mixed-phase cloud processes is needed. By combining retrieved mixed-phase cloud microphysical properties with in situ data and large-scale meteorological data, the project aim to better understand the generations of ice crystals in supercooled water clouds, the maintenance mechanisms of the arctic mixed-phase clouds, and their connections with large-scale dynamics. The project will try to develop a new retrieval algorithm to study more complex mixed-phase clouds observed at the ACRF SGP site. Compared with optically thin ice clouds, optically thick middle level ice clouds are less studied because of limited available tools. The project will develop a new two wavelength radar technique for optically thick ice cloud study at SGP site by combining the MMCR with the W-band radar measurements. With this new algorithm, the SGP site will have a better capability to study all ice clouds. Another area of the proposal is to generate long-term cloud type classification product for the multiple ACRF sites. The cloud type classification product will not only facilitates the generation of the integrated cloud product by applying different retrieval algorithms to different types of clouds operationally, but will also support other research to better understand cloud properties and to validate model simulations. The ultimate goal is to improve our cloud classification algorithm into a VAP.

  4. Stratus Cloud Structure from MM-Radar Transects and Satellite...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    modeling: * cloud-radiation interaction where correlations can trigger three-dimensional (3D) radiative transfer effects; and * dynamical cloud modeling where the goal is to...

  5. Joint retrievals of cloud and drizzle in marine boundary layer clouds using ground-based radar, lidar and zenith radiances

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fielding, M. D.; Chiu, J. C.; Hogan, R. J.; Feingold, G.; Eloranta, E.; O'Connor, E. J.; Cadeddu, M. P.

    2015-02-16

    Active remote sensing of marine boundary-layer clouds is challenging as drizzle drops often dominate the observed radar reflectivity. We present a new method to simultaneously retrieve cloud and drizzle vertical profiles in drizzling boundary-layer cloud using surface-based observations of radar reflectivity, lidar attenuated backscatter, and zenith radiances. Specifically, the vertical structure of droplet size and water content of both cloud and drizzle is characterised throughout the cloud. An ensemble optimal estimation approach provides full error statistics given the uncertainty in the observations. To evaluate the new method, we first perform retrievals using synthetic measurements from large-eddy simulation snapshots of cumulusmore » under stratocumulus, where cloud water path is retrieved with an error of 31 g m−2. The method also performs well in non-drizzling clouds where no assumption of the cloud profile is required. We then apply the method to observations of marine stratocumulus obtained during the Atmospheric Radiation Measurement MAGIC deployment in the northeast Pacific. Here, retrieved cloud water path agrees well with independent 3-channel microwave radiometer retrievals, with a root mean square difference of 10–20 g m−2.« less

  6. Joint retrievals of cloud and drizzle in marine boundary layer clouds using ground-based radar, lidar and zenith radiances

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fielding, M. D.; Chiu, J. C.; Hogan, R. J.; Feingold, G.; Eloranta, E.; O'Connor, E. J.; Cadeddu, M. P.

    2015-07-02

    Active remote sensing of marine boundary-layer clouds is challenging as drizzle drops often dominate the observed radar reflectivity. We present a new method to simultaneously retrieve cloud and drizzle vertical profiles in drizzling boundary-layer clouds using surface-based observations of radar reflectivity, lidar attenuated backscatter, and zenith radiances under conditions when precipitation does not reach the surface. Specifically, the vertical structure of droplet size and water content of both cloud and drizzle is characterised throughout the cloud. An ensemble optimal estimation approach provides full error statistics given the uncertainty in the observations. To evaluate the new method, we first perform retrievalsmore » using synthetic measurements from large-eddy simulation snapshots of cumulus under stratocumulus, where cloud water path is retrieved with an error of 31 g m-2. The method also performs well in non-drizzling clouds where no assumption of the cloud profile is required. We then apply the method to observations of marine stratocumulus obtained during the Atmospheric Radiation Measurement MAGIC deployment in the Northeast Pacific. Here, retrieved cloud water path agrees well with independent three-channel microwave radiometer retrievals, with a root mean square difference of 10–20 g m-2.« less

  7. A High Resolution Hydrometer Phase Classifier Based on Analysis of Cloud Radar Doppler Spectra.

    SciTech Connect (OSTI)

    Luke,E.; Kollias, P.

    2007-08-06

    The lifecycle and radiative properties of clouds are highly sensitive to the phase of their hydrometeors (i.e., liquid or ice). Knowledge of cloud phase is essential for specifying the optical properties of clouds, or else, large errors can be introduced in the calculation of the cloud radiative fluxes. Current parameterizations of cloud water partition in liquid and ice based on temperature are characterized by large uncertainty (Curry et al., 1996; Hobbs and Rangno, 1998; Intriery et al., 2002). This is particularly important in high geographical latitudes and temperature ranges where both liquid droplets and ice crystal phases can exist (mixed-phase cloud). The mixture of phases has a large effect on cloud radiative properties, and the parameterization of mixed-phase clouds has a large impact on climate simulations (e.g., Gregory and Morris, 1996). Furthermore, the presence of both ice and liquid affects the macroscopic properties of clouds, including their propensity to precipitate. Despite their importance, mixed-phase clouds are severely understudied compared to the arguably simpler single-phase clouds. In-situ measurements in mixed-phase clouds are hindered due to aircraft icing, difficulties distinguishing hydrometeor phase, and discrepancies in methods for deriving physical quantities (Wendisch et al. 1996, Lawson et al. 2001). Satellite-based retrievals of cloud phase in high latitudes are often hindered by the highly reflecting ice-covered ground and persistent temperature inversions. From the ground, the retrieval of mixed-phase cloud properties has been the subject of extensive research over the past 20 years using polarization lidars (e.g., Sassen et al. 1990), dual radar wavelengths (e.g., Gosset and Sauvageot 1992; Sekelsky and McIntosh, 1996), and recently radar Doppler spectra (Shupe et al. 2004). Millimeter-wavelength radars have substantially improved our ability to observe non-precipitating clouds (Kollias et al., 2007) due to their excellent sensitivity that enables the detection of thin cloud layers and their ability to penetrate several non-precipitating cloud layers. However, in mixed-phase clouds conditions, the observed Doppler moments are dominated by the highly reflecting ice crystals and thus can not be used to identify the cloud phase. This limits our ability to identify the spatial distribution of cloud phase and our ability to identify the conditions under which mixed-phase clouds form.

  8. Cloud Effects on Radiative Heating Rate Profiles over Darwin using ARM and A-train Radar/Lidar Observations

    SciTech Connect (OSTI)

    Thorsen, Tyler J.; Fu, Qiang; Comstock, Jennifer M.

    2013-06-11

    Observations of clouds from the ground-based U.S. Department of Energy Atmospheric Radiation Measurement program (ARM) and satellite-based A-train are used to compute cloud radiative forcing profiles over the ARM Darwin, Australia site. Cloud properties are obtained from both radar (the ARM Millimeter Cloud Radar (MMCR) and the CloudSat satellite in the A-train) and lidar (the ARM Micropulse lidar (MPL) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite in the A-train) observations. Cloud microphysical properties are taken from combined radar and lidar retrievals for ice clouds and radar only or lidar only retrievals for liquid clouds. Large, statistically significant differences of up to 1.43 K/day exist between the mean ARM and A-train net cloud radiative forcing profiles. The majority of the difference in cloud radiative forcing profiles is shown to be due to a large difference in the cloud fraction above 12 km. Above this altitude the A-train cloud fraction is significantly larger because more clouds are detected by CALIPSO than by the ground-based MPL. It is shown that the MPL is unable to observe as many high clouds as CALIPSO due to being more frequently attenuated and a poorer sensitivity even in otherwise clear-sky conditions. After accounting for cloud fraction differences and instrument sampling differences due to viewing platform we determined that differences in cloud radiative forcing due to the retrieved ice cloud properties is relatively small. This study demonstrates that A-train observations are better suited for the calculation cloud radiative forcing profiles. In addition, we find that it is necessary to supplement CloudSat with CALIPSO observations to obtain accurate cloud radiative forcing profiles since a large portion of clouds at Darwin are detected by CALIPSO only.

  9. Constructing a Merged Cloud-Precipitation Radar Dataset for Tropical Convective Clouds during the DYNAMO/AMIE Experiment at Addu Atoll

    SciTech Connect (OSTI)

    Feng, Zhe; McFarlane, Sally A.; Schumacher, Courtney; Ellis, Scott; Comstock, Jennifer M.; Bharadwaj, Nitin

    2014-05-16

    To improve understanding of the convective processes key to the Madden-Julian-Oscillation (MJO) initiation, the Dynamics of the MJO (DYNAMO) and Atmospheric Radiation Measurement MJO Investigation Experiment (AMIE) collected four months of observations from three radars, the S-band Polarization Radar (S-Pol), the C-band Shared Mobile Atmospheric Research & Teaching Radar (SMART-R), and Ka-band Zenith Radar (KAZR) on Addu Atoll in the tropical Indian Ocean. This study compares the measurements from the S-Pol and SMART-R to those from the more sensitive KAZR in order to characterize the hydrometeor detection capabilities of the two scanning precipitation radars. Frequency comparisons for precipitating convective clouds and non-precipitating high clouds agree much better than non-precipitating low clouds for both scanning radars due to issues in ground clutter. On average, SMART-R underestimates convective and high cloud tops by 0.3 to 1.1 km, while S-Pol underestimates cloud tops by less than 0.4 km for these cloud types. S-Pol shows excellent dynamic range in detecting various types of clouds and therefore its data are well suited for characterizing the evolution of the 3D cloud structures, complementing the profiling KAZR measurements. For detecting non-precipitating low clouds and thin cirrus clouds, KAZR remains the most reliable instrument. However, KAZR is attenuated in heavy precipitation and underestimates cloud top height due to rainfall attenuation 4.3% of the time during DYNAMO/AMIE. An empirical method to correct the KAZR cloud top heights is described, and a merged radar dataset is produced to provide improved cloud boundary estimates, microphysics and radiative heating retrievals.

  10. A Comparison of ARM Cloud Radar Profiles with MMF Simulated Radar...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    state, and did the same for the model output. - By profiles of cloud occurrence, we mean (at given altitude above ground level) the relative frequency that a cloud was...

  11. Scanning ARM Cloud Radars. Part II: Data Quality Control and Processing

    SciTech Connect (OSTI)

    Kollias, Pavlos; Jo, Ieng; Borque, Paloma; Tatarevic, Aleksandra; Lamer, Katia; Bharadwaj, Nitin; Widener, Kevin B.; Johnson, Karen L.; Clothiaux, Eugene E.

    2014-03-01

    The Scanning ARM Cloud Radars (SACRs) are the primary instruments for documenting the four-dimensional structure and evolution of clouds within a 20-30 km radius from the ARM fixed and mobile sites. Here, the post-processing of the calibrated SACR measurements is discussed. First, a feature mask algorithm that objectively determines the presence of significant radar returns is described. The feature mask algorithm is based on the statistical properties of radar receiver noise. It accounts for atmospheric emission and is applicable even for SACR profiles with few or no signal-free range gates. Using the nearest-in-time atmospheric sounding, the SACR radar reflectivities are corrected for gaseous attenuation (water vapor and oxygen) using a line-by-line absorption model. Despite having a high pulse repetition frequency, the SACR has a narrow Nyquist velocity limit and thus Doppler velocity folding is commonly observed. An unfolding algorithm that makes use of a first guess for the true Doppler velocity using horizontal wind measurements from the nearest sounding is described. The retrieval of the horizontal wind profile from the HS-RHI SACR scan observations and/or nearest sounding is described. The retrieved horizontal wind profile can be used to adaptively configure SACR scan strategies that depend on wind direction. Several remaining challenges are discussed, including the removal of insect and second-trip echoes. The described algorithms significantly enhance SACR data quality and constitute an important step towards the utilization of SACR measurements for cloud research.

  12. Scanning ARM Cloud Radars Part II: Data Quality Control and Processing

    SciTech Connect (OSTI)

    Kollias, Pavlos; Jo, Ieng; Borque, Paloma; Tatarevic, Aleksandra; Lamer, Katia; Bharadwaj, Nitin; Widener, Kevin B.; Johnson, Karen; Clothiaux, Eugene E.

    2014-03-01

    The Scanning ARM Cloud Radars (SACRs) are the primary instruments for documenting the four-dimensional structure and evolution of clouds within a 20-30 km radius from the ARM fixed and mobile sites. Here, the post-processing of the calibrated SACR measurements is discussed. First, a feature mask algorithm that objectively determines the presence of significant radar returns is described. The feature mask algorithm is based on the statistical properties of radar receiver noise. It accounts for atmospheric emission and is applicable even for SACR profiles with few or no signal-free range gates. Using the nearest-in-time atmospheric sounding, the SACR radar reflectivities are corrected for gaseous attenuation (water vapor and oxygen) using a line-by-line absorption model. Despite having a high pulse repetition frequency, the SACR has a narrow Nyquist velocity limit and thus Doppler velocity folding is commonly observed. An unfolding algorithm that makes use of a first guess for the true Doppler velocity using horizontal wind measurements from the nearest sounding is described. The retrieval of the horizontal wind profile from the Hemispherical Sky Range Height Indicator SACR scan observations and/or nearest sounding is described. The retrieved horizontal wind profile can be used to adaptively configure SACR scan strategies that depend on wind direction. Several remaining challenges are discussed, including the removal of insect and second-trip echoes. The described algorithms significantly enhance SACR data quality and constitute an important step towards the utilization of SACR measurements for cloud research.

  13. ARM: X-Band Scanning ARM Cloud Radar (XSACR) Hemispherical Sky RHI Scans (6 horizon-to-horizon scans at 30-degree azimuth intervals)

    SciTech Connect (OSTI)

    Dan Nelson; Joseph Hardin; Iosif Lindenmaier; Bradley Isom; Karen Johnson; Nitin Bharadwaj

    2011-09-14

    X-Band Scanning ARM Cloud Radar (XSACR) Hemispherical Sky RHI Scans (6 horizon-to-horizon scans at 30-degree azimuth intervals)

  14. ARM: Ka-Band Scanning ARM Cloud Radar (KASACR) Hemispherical Sky RHI Scan (6 horizon-to-horizon scans at 30-degree azimuth intervals)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Dan Nelson; Joseph Hardin; Iosif (Andrei) Lindenmaier; Bradley Isom; Karen Johnson; Nitin Bharadwaj

    2011-05-24

    Ka-Band Scanning ARM Cloud Radar (KASACR) Hemispherical Sky RHI Scan (6 horizon-to-horizon scans at 30-degree azimuth intervals)

  15. ARM: W-Band Scanning ARM Cloud Radar (W-SACR) Hemispherical Sky RHI Scans (6 horizon-to-horizon scans at 30-degree azimuth intervals)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Dan Nelson; Joseph Hardin; Iosif (Andrei) Lindenmaier; Bradley Isom; Karen Johnson; Nitin Bharadwaj

    1990-01-01

    W-Band Scanning ARM Cloud Radar (W-SACR) Hemispherical Sky RHI Scans (6 horizon-to-horizon scans at 30-degree azimuth intervals)

  16. ARM: X-Band Scanning ARM Cloud Radar (XSACR) Hemispherical Sky RHI Scans (6 horizon-to-horizon scans at 30-degree azimuth intervals)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Dan Nelson; Joseph Hardin; Iosif (Andrei) Lindenmaier; Bradley Isom; Karen Johnson; Nitin Bharadwaj

    X-Band Scanning ARM Cloud Radar (XSACR) Hemispherical Sky RHI Scans (6 horizon-to-horizon scans at 30-degree azimuth intervals)

  17. ARM: W-Band Scanning ARM Cloud Radar (W-SACR) Hemispherical Sky RHI Scans (6 horizon-to-horizon scans at 30-degree azimuth intervals)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Dan Nelson; Joseph Hardin; Iosif (Andrei) Lindenmaier; Bradley Isom; Karen Johnson; Nitin Bharadwaj

    W-Band Scanning ARM Cloud Radar (W-SACR) Hemispherical Sky RHI Scans (6 horizon-to-horizon scans at 30-degree azimuth intervals)

  18. ARM: Ka-Band Scanning ARM Cloud Radar (KASACR) Hemispherical Sky RHI Scan (6 horizon-to-horizon scans at 30-degree azimuth intervals)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Dan Nelson; Joseph Hardin; Iosif (Andrei) Lindenmaier; Bradley Isom; Karen Johnson; Nitin Bharadwaj

    Ka-Band Scanning ARM Cloud Radar (KASACR) Hemispherical Sky RHI Scan (6 horizon-to-horizon scans at 30-degree azimuth intervals)

  19. On the relationship among cloud turbulence, droplet formation and drizzle as viewed by Doppler radar, microwave radiometer and lidar

    SciTech Connect (OSTI)

    Feingold, G.; Frisch, A.S.; Cotton, W.R.

    1999-09-01

    Cloud radar, microwave radiometer, and lidar remote sensing data acquired during the Atlantic Stratocumulus Transition Experiment (ASTEX) are analyzed to address the relationship between (1) drop number concentration and cloud turbulence as represented by vertical velocity and vertical velocity variance and (2) drizzle formation and cloud turbulence. Six cases, each of about 12 hours duration, are examined; three of these cases are characteristic of nondrizzling boundary layers and three of drizzling boundary layers. In all cases, microphysical retrievals are only performed when drizzle is negligible (radar reflectivity{lt}{minus}17dBZ). It is shown that for the cases examined, there is, in general, no correlation between drop concentration and cloud base updraft strength, although for two of the nondrizzling cases exhibiting more classical stratocumulus features, these two parameters are correlated. On drizzling days, drop concentration and cloud-base vertical velocity were either not correlated or negatively correlated. There is a significant positive correlation between drop concentration and mean in-cloud vertical velocity variance for both nondrizzling boundary layers (correlation coefficient r=0.45) and boundary layers that have experienced drizzle (r=0.38). In general, there is a high correlation (r{gt}0.5) between radar reflectivity and in-cloud vertical velocity variance, although one of the boundary layers that experienced drizzle exhibited a negative correlation between these parameters. However, in the subcloud region, all boundary layers that experienced drizzle exhibit a negative correlation between radar reflectivity and vertical velocity variance. {copyright} 1999 American Geophysical Union

  20. ARM - Measurement - Radar polarization

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    polarization ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Radar polarization The temporal and geometric behavior of the electric field vector of an electromagnetic wave transmitted or received by a radar system, e.g. elliptical polarization, differential reflectivity, phase shift, co-polar correlation coefficient, linear depolarization ratio. Categories Cloud Properties Instruments The above

  1. Ice Concentration Retrieval in Stratiform Mixed-phase Clouds Using Cloud Radar Reflectivity Measurements and 1D Ice Growth Model Simulations

    SciTech Connect (OSTI)

    Zhang, Damao; Wang, Zhien; Heymsfield, Andrew J.; Fan, Jiwen; Luo, Tao

    2014-10-01

    Measurement of ice number concentration in clouds is important but still challenging. Stratiform mixed-phase clouds (SMCs) provide a simple scenario for retrieving ice number concentration from remote sensing measurements. The simple ice generation and growth pattern in SMCs offers opportunities to use cloud radar reflectivity (Ze) measurements and other cloud properties to infer ice number concentration quantitatively. To understand the strong temperature dependency of ice habit and growth rate quantitatively, we develop a 1-D ice growth model to calculate the ice diffusional growth along its falling trajectory in SMCs. The radar reflectivity and fall velocity profiles of ice crystals calculated from the 1-D ice growth model are evaluated with the Atmospheric Radiation Measurements (ARM) Climate Research Facility (ACRF) ground-based high vertical resolution radar measurements. Combining Ze measurements and 1-D ice growth model simulations, we develop a method to retrieve the ice number concentrations in SMCs at given cloud top temperature (CTT) and liquid water path (LWP). The retrieved ice concentrations in SMCs are evaluated with in situ measurements and with a three-dimensional cloud-resolving model simulation with a bin microphysical scheme. These comparisons show that the retrieved ice number concentrations are within an uncertainty of a factor of 2, statistically.

  2. Using dynamic interferometric synthetic aperature radar (InSAR) to image fast-moving surface waves

    DOE Patents [OSTI]

    Vincent, Paul

    2005-06-28

    A new differential technique and system for imaging dynamic (fast moving) surface waves using Dynamic Interferometric Synthetic Aperture Radar (InSAR) is introduced. This differential technique and system can sample the fast-moving surface displacement waves from a plurality of moving platform positions in either a repeat-pass single-antenna or a single-pass mode having a single-antenna dual-phase receiver or having dual physically separate antennas, and reconstruct a plurality of phase differentials from a plurality of platform positions to produce a series of desired interferometric images of the fast moving waves.

  3. Cloud Properties from Doppler Radar Spectra - a Growing Suite of Information Extraction Algorithms

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    from Doppler Radar Spectra - a Growing Suite of Information Extraction Algorithms Edward Luke 1 , Pavlos Kollias 2 , Matthew Shupe 3 , Karen Johnson 1 , Eugene Clothiaux 4 1. Brookhaven National Laboratory 2. McGill University 3. CIRES/NOAA/ETL 4. Penn State University C F B A E D Lidar Prediction Algorithm Depolarization C F B A E D Backscatter DOPPLER RADAR SPECTRA HYDROMETEOR PHASE CLASSIFICATION MIXED LIQUID SOLID MIXED LIQUID SOLID Shupe Multi-instrument Technique Doppler Radar Spectra

  4. Laser- and Radar-based Mission Concepts for Suborbital and Spaceborne Monitoring of Seismic Surface Waves

    SciTech Connect (OSTI)

    Foxall, W; Schultz, C A; Tralli, D M

    2004-09-21

    The development of a suborbital or spaceborne system to monitor seismic waves poses an intriguing prospect for advancing the state of seismology. This capability would enable an unprecedented global mapping of the velocity structure of the earth's crust, understanding of earthquake rupture dynamics and wave propagation effects, and event source location, characterization and discrimination that are critical for both fundamental earthquake research and nuclear non-proliferation applications. As part of an ongoing collaboration between LLNL and JPL, an advanced mission concept study assessed architectural considerations and operational and data delivery requirements, extending two prior studies by each organization--a radar-based satellite system (JPL) for earthquake hazard assessment and a feasibility study of space- or UAV-based laser seismometer systems (LLNL) for seismic event monitoring. Seismic wave measurement requirements include lower bounds on detectability of specific seismic sources of interest and wave amplitude accuracy for different levels of analysis, such as source characterization, discrimination and tomography, with a 100 {micro}m wave amplitude resolution for waves nominally traveling 5 km/s, an upper frequency bound based on explosion and earthquake surface displacement spectra, and minimum horizontal resolution (1-5 km) and areal coverage, in general and for targeted observations. For a radar system, corresponding engineering and operational factors include: Radar frequency (dictated by required wave amplitude measurement accuracy and maximizing ranging, Doppler or interferometric sensitivity), time sampling (maximum seismic wave frequency and velocity), and overall system considerations such as mass, power and data rate. Technical challenges include characterization of, and compensation for, phase distortion resulting from atmospheric and ionospheric perturbations and turbulence, and effects of ground scattering characteristics and seismic ground motion on phase coherence over interferometric time intervals. Since the temporal sampling requirement may be finer than that possible for a high-altitude sensor to traverse a synthetic aperture length, a geostationary, real-aperture Ka-band system or constellation for equatorial and moderate-latitude global coverage is one option considered. The short wavelength would maximize interferometric sensitivity to small surface displacements and minimize required antenna area. Engineering issues include the design and deployment of a large ({approx} 100m) fixed aperture antenna; and fast electronic beam steering (entire aperture within nominal 1 s interferometric interval) with high-efficiency integrated transmit/receive modules. For a suborbital system, platform instability is an issue whereas at high earth orbit signal-to-noise and attendant power requirements dominate. Data delivery requirements include large-volume data storage and transmission; development of real-time, on-board event detection and processing algorithms, and data management structures for these very large data sets. A far-term roadmap would comprise a proof-of-concept demonstration using a laser or radar system mounted on a stratospheric balloon or UAV to image seismic wavefields from planned events (e.g. large mine blasts and/or purpose-designed explosions) and earthquake targets of opportunity. The technological challenges to developing any such seismic monitoring system, whether laser- or radar-based, are at this stage enormous. However, these concept studies suggest the long-term feasibility of such a system and drive the development of enabling technologies while fostering collaboration on meeting scientific and operational challenges of agencies such as NASA, DOE and DoD.

  5. A study of cloud and drizzle properties in the Azores using Doppler Radar spectra

    SciTech Connect (OSTI)

    Luke, E.; Remillard, J.; Kollias, P.

    2010-03-15

    Understanding the onset of coalescence in warm clouds is key in our effort to improve cloud representation in numerical models. Coalescence acts at small scales, and its study requires detailed high-resolution dynamical and microphysical measurements from a comprehensive suite of instruments over a wide range of environmental conditions (e.g., aerosol loading). The first AMF is currently in its second year of a two-year deployment at Graciosa Island in the Azores, offering the opportunity to collect a long data set from a stable land-based platform in a marine stratocumulus regime. In this study, recorded WACR Doppler spectra are used to characterize the properties of Doppler spectra from warm clouds with and without drizzle, and from drizzle only, in an effort to observe the transition (onset) to precipitation in clouds. A retrieval technique that decomposes observed Doppler spectra into their cloud and/or drizzle components is applied in order to quantify drizzle growth.

  6. TRIGGERING COLLAPSE OF THE PRESOLAR DENSE CLOUD CORE AND INJECTING SHORT-LIVED RADIOISOTOPES WITH A SHOCK WAVE. II. VARIED SHOCK WAVE AND CLOUD CORE PARAMETERS

    SciTech Connect (OSTI)

    Boss, Alan P.; Keiser, Sandra A. E-mail: keiser@dtm.ciw.edu

    2013-06-10

    A variety of stellar sources have been proposed for the origin of the short-lived radioisotopes that existed at the time of the formation of the earliest solar system solids, including Type II supernovae (SNe), asymptotic giant branch (AGB) and super-AGB stars, and Wolf-Rayet star winds. Our previous adaptive mesh hydrodynamics models with the FLASH2.5 code have shown which combinations of shock wave parameters are able to simultaneously trigger the gravitational collapse of a target dense cloud core and inject significant amounts of shock wave gas and dust, showing that thin SN shocks may be uniquely suited for the task. However, recent meteoritical studies have weakened the case for a direct SN injection to the presolar cloud, motivating us to re-examine a wider range of shock wave and cloud core parameters, including rotation, in order to better estimate the injection efficiencies for a variety of stellar sources. We find that SN shocks remain as the most promising stellar source, though planetary nebulae resulting from AGB star evolution cannot be conclusively ruled out. Wolf-Rayet (WR) star winds, however, are likely to lead to cloud core shredding, rather than to collapse. Injection efficiencies can be increased when the cloud is rotating about an axis aligned with the direction of the shock wave, by as much as a factor of {approx}10. The amount of gas and dust accreted from the post-shock wind can exceed that injected from the shock wave, with implications for the isotopic abundances expected for a SN source.

  7. Using Radar, Lidar and Radiometer Data from NSA and SHEBA to Quantify Cloud Property Effects on the Surface Heat Budget in the Arctic

    SciTech Connect (OSTI)

    Janet Intrieri; Mathhew Shupe

    2005-01-01

    Cloud and radiation data from two distinctly different Arctic areas are analyzed to study the differences between coastal Alaskan and open Arctic Ocean region clouds and their respective influence on the surface radiation budget. The cloud and radiation datasets were obtained from (1) the DOE North Slope of Alaska (NSA) facility in the coastal town of Barrow, Alaska, and (2) the SHEBA field program, which was conducted from an icebreaker frozen in, and drifting with, the sea-ice for one year in the Western Arctic Ocean. Radar, lidar, radiometer, and sounding measurements from both locations were used to produce annual cycles of cloud occurrence and height, atmospheric temperature and humidity, surface longwave and shortwave broadband fluxes, surface albedo, and cloud radiative forcing. In general, both regions revealed a similar annual trend of cloud occurrence fraction with minimum values in winter (60-75%) and maximum values during spring, summer and fall (80-90%). However, the annual average cloud occurrence fraction for SHEBA (76%) was lower than the 6-year average cloud occurrence at NSA (92%). Both Arctic areas also showed similar annual cycle trends of cloud forcing with clouds warming the surface through most of the year and a period of surface cooling during the summer, when cloud shading effects overwhelm cloud greenhouse effects. The greatest difference between the two regions was observed in the magnitude of the cloud cooling effect (i.e., shortwave cloud forcing), which was significantly stronger at NSA and lasted for a longer period of time than at SHEBA. This is predominantly due to the longer and stronger melt season at NSA (i.e., albedo values that are much lower coupled with Sun angles that are somewhat higher) than the melt season observed over the ice pack at SHEBA. Longwave cloud forcing values were comparable between the two sites indicating a general similarity in cloudiness and atmospheric temperature and humidity structure between the two regions.

  8. Determination of Large-Scale Cloud Ice Water Concentration by Combining Surface Radar and Satellite Data in Support of ARM SCM Activities

    SciTech Connect (OSTI)

    Liu, Guosheng

    2013-03-15

    Single-column modeling (SCM) is one of the key elements of Atmospheric Radiation Measurement (ARM) research initiatives for the development and testing of various physical parameterizations to be used in general circulation models (GCMs). The data required for use with an SCM include observed vertical profiles of temperature, water vapor, and condensed water, as well as the large-scale vertical motion and tendencies of temperature, water vapor, and condensed water due to horizontal advection. Surface-based measurements operated at ARM sites and upper-air sounding networks supply most of the required variables for model inputs, but do not provide the horizontal advection term of condensed water. Since surface cloud radar and microwave radiometer observations at ARM sites are single-point measurements, they can provide the amount of condensed water at the location of observation sites, but not a horizontal distribution of condensed water contents. Consequently, observational data for the large-scale advection tendencies of condensed water have not been available to the ARM cloud modeling community based on surface observations alone. This lack of advection data of water condensate could cause large uncertainties in SCM simulations. Additionally, to evaluate GCMs’ cloud physical parameterization, we need to compare GCM results with observed cloud water amounts over a scale that is large enough to be comparable to what a GCM grid represents. To this end, the point-measurements at ARM surface sites are again not adequate. Therefore, cloud water observations over a large area are needed. The main goal of this project is to retrieve ice water contents over an area of 10 x 10 deg. surrounding the ARM sites by combining surface and satellite observations. Built on the progress made during previous ARM research, we have conducted the retrievals of 3-dimensional ice water content by combining surface radar/radiometer and satellite measurements, and have produced 3-D cloud ice water contents in support of cloud modeling activities. The approach of the study is to expand a (surface) point measurement to an (satellite) area measurement. That is, the study takes the advantage of the high quality cloud measurements (particularly cloud radar and microwave radiometer measurements) at the point of the ARM sites. We use the cloud ice water characteristics derived from the point measurement to guide/constrain a satellite retrieval algorithm, then use the satellite algorithm to derive the 3-D cloud ice water distributions within an 10° (latitude) x 10° (longitude) area. During the research period, we have developed, validated and improved our cloud ice water retrievals, and have produced and archived at ARM website as a PI-product of the 3-D cloud ice water contents using combined satellite high-frequency microwave and surface radar observations for SGP March 2000 IOP and TWP-ICE 2006 IOP over 10 deg. x 10 deg. area centered at ARM SGP central facility and Darwin sites. We have also worked on validation of the 3-D ice water product by CloudSat data, synergy with visible/infrared cloud ice water retrievals for better results at low ice water conditions, and created a long-term (several years) of ice water climatology in 10 x 10 deg. area of ARM SGP and TWP sites and then compared it with GCMs.

  9. The Ability of MM5 to Simulate Ice Clouds: Systematic Comparison between Simulated and Measured Fluxes and Lidar/Radar Profiles at SIRTA Atmospheric Observatory

    SciTech Connect (OSTI)

    Chiriaco, M.; Vautard, R.; Chepfer, H.; Haeffelin, M.; Wanherdrick, Y.; Morille, Y.; Protat, A.; Dudhia, J.

    2005-03-18

    Ice clouds play a major role in the radiative energy budget of the Earth-atmosphere system (Liou 1986). Their radiative effect is governed primarily by the equilibrium between their albedo and greenhouse effects. Both macrophysical and microphysical properties of ice clouds regulate this equilibrium. For quantifying the effect of these clouds onto climate and weather systems, they must be properly characterized in atmospheric models. In this paper we use remote-sensing measurements from the SIRTA ground based atmospheric observatory (Site Instrumental de Recherche par Teledetection Atmospherique, http://sirta.lmd.polytechnique.fr). Lidar and radar observations taken over 18 months are used, in order to gain statistical confidence in the model evaluation. Along this period of time, 62 days are selected for study because they contain parts of ice clouds. We use the ''model to observations'' approach by simulating lidar and radar signals from MM5 outputs. Other more classical variables such as shortwave and longwave radiative fluxes are also used. Four microphysical schemes, among which that proposed by Reisner et al. (1998) with original or modified parameterizations of particle terminal fall velocities (Zurovac-Jevtic and Zhang 2003, Heymsfield and Donner 1990), and the simplified Dudhia (1989) scheme are evaluated in this study.

  10. The Role of Gravity Waves in the Formation and Organization of Clouds during TWPICE

    SciTech Connect (OSTI)

    Reeder, Michael J.; Lane, Todd P.; Hankinson, Mai Chi Nguyen

    2013-09-27

    All convective clouds emit gravity waves. While it is certain that convectively-generated waves play important parts in determining the climate, their precise roles remain uncertain and their effects are not (generally) represented in climate models. The work described here focuses mostly on observations and modeling of convectively-generated gravity waves, using the intensive observations from the DoE-sponsored Tropical Warm Pool International Cloud Experiment (TWP-ICE), which took place in Darwin, from 17 January to 13 February 2006. Among other things, the research has implications the part played by convectively-generated gravity waves in the formation of cirrus, in the initiation and organization of further convection, and in the subgrid-scale momentum transport and associated large-scale stresses imposed on the troposphere and stratosphere. The analysis shows two groups of inertia-gravity waves are detected: group L in the middle stratosphere during the suppressed monsoon period, and group S in the lower stratosphere during the monsoon break period. Waves belonging to group L propagate to the south-east with a mean intrinsic period of 35 h, and have vertical and horizontal wavelengths of about 5-6 km and 3000-6000 km, respectively. Ray tracing calculations indicate that these waves originate from a deep convective region near Indonesia. Waves belonging to group S propagate to the south-south-east with an intrinsic period, vertical wavelength and horizontal wavelength of about 45 h, 2 km and 2000-4000 km, respectively. These waves are shown to be associated with shallow convection in the oceanic area within about 1000 km of Darwin. The intrinsic periods of high-frequency waves are estimated to be between 20-40 minutes. The high-frequency wave activity in the stratosphere, defined by mass-weighted variance of the vertical motion of the sonde, has a maximum following the afternoon local convection indicating that these waves are generated by local convection. The wave activity is strongest in the lower stratosphere below 22 km and, during the suppressed monsoon period, is modulated with a 3-4-day period. The concentration of the wave activity in the lower stratosphere is consistent with the properties of the environment in which these waves propagate, whereas its 3-4-day modulation is explained by the variation of the convection activity in the TWP-ICE domain. At low rainfall intensity the wave activity increases as rainfall intensity increases. At high values of rainfall intensity, however, the wave activity associated with deep convective clouds is independent of the rainfall intensity. The convection and gravity waves observed during TWP-ICE are simulated with the Weather Research and Forecasting (WRF) Model. These simulations are compared with radiosonde observations described above and are used to determine some of the properties of convectively generated gravity waves. The gravity waves appear to be well simulated by the model. The model is used to explore the relationships between the convection, the gravity waves and cirrus.

  11. Comparing Clouds Using Cloud Radar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    How To Graph Goals: The goal of this activity is to learn how to make a coordinate or line graph. Materials: Graph paper Pencil Introduction: Graphs and charts are great because they communicate information visually. Graphs are often used by scientists, but also by newspapers, magazines and businesses around the world. Sometimes, complicated information is difficult to understand and needs an illustration. Other times, a graph or chart helps impress people by getting the point across quickly and

  12. TC_CLOUD_REGIME.cdr

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    intensity (e.g. May and Ballinger, 2007) Resulting Cloud Properties Examine rain DSD using polarimetric radar Examine ice cloud properties using MMCR and MPL Expect...

  13. Triggering collapse of the presolar dense cloud core and injecting short-lived radioisotopes with a shock wave. III. Rotating three-dimensional cloud cores

    SciTech Connect (OSTI)

    Boss, Alan P.; Keiser, Sandra A.

    2014-06-10

    A key test of the supernova triggering and injection hypothesis for the origin of the solar system's short-lived radioisotopes is to reproduce the inferred initial abundances of these isotopes. We present here the most detailed models to date of the shock wave triggering and injection process, where shock waves with varied properties strike fully three-dimensional, rotating, dense cloud cores. The models are calculated with the FLASH adaptive mesh hydrodynamics code. Three different outcomes can result: triggered collapse leading to fragmentation into a multiple protostar system; triggered collapse leading to a single protostar embedded in a protostellar disk; or failure to undergo dynamic collapse. Shock wave material is injected into the collapsing clouds through Rayleigh-Taylor fingers, resulting in initially inhomogeneous distributions in the protostars and protostellar disks. Cloud rotation about an axis aligned with the shock propagation direction does not increase the injection efficiency appreciably, as the shock parameters were chosen to be optimal for injection even in the absence of rotation. For a shock wave from a core-collapse supernova, the dilution factors for supernova material are in the range of ?10{sup 4} to ?3 10{sup 4}, in agreement with recent laboratory estimates of the required amount of dilution for {sup 60}Fe and {sup 26}Al. We conclude that a type II supernova remains as a promising candidate for synthesizing the solar system's short-lived radioisotopes shortly before their injection into the presolar cloud core by the supernova's remnant shock wave.

  14. ARM - Field Campaign - NSA Scanning Radar IOP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    scanning radar observations for a variety of sampling modes assess the real-time signal processing of the 3-cm wave precipitation scanning radar by collecting IQ time...

  15. Microwave and Millimeter-Wave Radiometric Studies of Temperature, Water Vapor and Clouds

    SciTech Connect (OSTI)

    Westwater, Edgeworth

    2011-05-06

    The importance of accurate measurements of column amounts of water vapor and cloud liquid has been well documented by scientists within the Atmospheric Radiation Measurement (ARM) Program. At the North Slope of Alaska (NSA), both microwave radiometers (MWR) and the MWRProfiler (MWRP), been used operationally by ARM for passive retrievals of the quantities: Precipitable Water Vapor (PWV) and Liquid Water Path (LWP). However, it has been convincingly shown that these instruments are inadequate to measure low amounts of PWV and LWP. In the case of water vapor, this is especially important during the Arctic winter, when PWV is frequently less than 2 mm. For low amounts of LWP (< 50 g/m{sup 2}), the MWR and MWRP retrievals have an accuracy that is also not acceptable. To address some of these needs, in March-April 2004, NOAA and ARM conducted the NSA Arctic Winter Radiometric Experiment - Water Vapor Intensive Operational Period at the ARM NSA/Adjacent Arctic Ocean (NSA/AAO) site. After this experiment, the radiometer group at NOAA moved to the Center for Environmental Technology (CET) of the Department of Electrical and Computer Engineering of the University of Colorado at Boulder. During this 2004 experiment, a total of 220 radiosondes were launched, and radiometric data from 22.235 to 380 GHz were obtained. Primary instruments included the ARM MWR and MWRP, a Global Positioning System (GPS), as well as the CET Ground-based Scanning Radiometer (GSR). We have analyzed data from these instruments to answer several questions of importance to ARM, including: (a) techniques for improved water vapor measurements; (b) improved calibration techniques during cloudy conditions; (c) the spectral response of radiometers to a variety of conditions: clear, liquid, ice, and mixed phase clouds; and (d) forward modeling of microwave and millimeter wave brightness temperatures from 22 to 380 GHz. Many of these results have been published in the open literature. During the third year of this contract, we participated in another ARM-sponsored experiment at the NSA during February-March 2007. This experiment is called the Radiative Heating in Underexplored Bands Campaign (RHUBC) and the GSR was operated successfully for the duration of the campaign. One of the principal goals of the experiment was to provide retrievals of water vapor during PWV amounts less than 2 mm and to compare GSR data with ARM radiometers and radiosondes. A secondary goal was to compare the radiometric response of the microwave and millimeter wavelength radiometers to water and ice clouds. In this final report, we will include the separate progress reports for each of the three years of the project and follow with a section on major accomplishments of the project.

  16. ARM - Measurement - Radar Doppler

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Doppler ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Radar Doppler The power spectrum and moments of the radar signal expressed as a function of Doppler frequency or Doppler velocity. It may be thought of as the reflectivity weighted radial velocity distribution of the scatterers in a distributed target. Categories Cloud Properties Instruments The above measurement is considered scientifically

  17. ARM - Midlatitude Continental Convective Clouds Experiment (MC3E): Multi-Frequency Profilers, S-band Radar (williams-s_band)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Williams, Christopher

    2012-11-06

    This data was collected by the NOAA 449-MHz and 2.8-GHz profilers in support of the Department of Energy (DOE) and NASA sponsored Mid-latitude Continental Convective Cloud Experiment (MC3E). The profiling radars were deployed in Northern Oklahoma at the DOE Atmospheric Radiation Mission (ARM) Southern Great Plans (SGP) Central Facility from 22 April through 6 June 2011. NOAA deployed three instruments: a Parsivel disdrometer, a 2.8-GHz profiler, and a 449-MHz profiler. The parasivel provided surface estimates of the raindrop size distribution and is the reference used to absolutely calibrate the 2.8 GHz profiler. The 2.8-GHz profiler provided unattenuated reflectivity profiles of the precipitation. The 449-MHz profiler provided estimates of the vertical air motion during precipitation from near the surface to just below the freezing level. By using the combination of 2.8-GHz and 449-MHz profiler observations, vertical profiles of raindrop size distributions can be retrieved. The profilers are often reference by their frequency band: the 2.8-GHz profiler operates in the S-band and the 449-MHz profiler operates in the UHF band. The raw observations are available as well as calibrated spectra and moments. This document describes how the instruments were deployed, how the data was collected, and the format of the archived data.

  18. Towards a Characterization of Arctic Mixed-Phase Clouds

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    manual classification of cloud phase. Using collocated cloud radar and depolarization lidar observations, it is shown that mixed-phase conditions have a high correlation with a...

  19. ARM - Field Campaign - Measuring Clouds at SGP with Stereo Photogramme...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the form of the Point Cloud of Cloud Points Product (PCCPP). The PCCPP will: provide context on life-cycle stage and cloud position for vertically pointing radars, lidars, and...

  20. Ka-Band ARM Zenith Radar (KAZR) Instrument Handbook

    SciTech Connect (OSTI)

    Widener, K; Bharadwaj, N; Johnson, K

    2012-03-06

    The Ka-band ARM zenith radar (KAZR) is a zenith-pointing Doppler cloud radar operating at approximately 35 GHz. The KAZR is an evolutionary follow-on radar to ARM's widely successful millimeter-wavelength cloud radar (MMCR). The main purpose of the KAZR is to provide vertical profiles of clouds by measuring the first three Doppler moments: reflectivity, radial Doppler velocity, and spectra width. At the sites where the dual-polarization measurements are made, the Doppler moments for the cross-polarization channel are also available. In addition to the moments, velocity spectra are also continuously recorded for each range gate.

  1. Properties of tropical convection observed by ARM millimeter-radars

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Properties of tropical convection observed by ARM millimeter-radars Haynes, John Colorado State University Stephens, Graeme Colorado State University Category: Cloud Properties The results of an analysis of tropical cloud systems observed from a variety of vertically pointing radar systems are described. In particular, observations taken during five years of operation of the ARM millimeter wavelength radar system (MMCR) at Manus Island in the Tropical West Pacific region are characterized into

  2. Doppler radar flowmeter

    DOE Patents [OSTI]

    Petlevich, Walter J. (Uniontown, PA); Sverdrup, Edward F. (Adamsburg, PA)

    1978-01-01

    A Doppler radar flowmeter comprises a transceiver which produces an audio frequency output related to the Doppler shift in frequency between radio waves backscattered from particulate matter carried in a fluid and the radiated radio waves. A variable gain amplifier and low pass filter are provided for amplifying and filtering the transceiver output. A frequency counter having a variable triggering level is also provided to determine the magnitude of the Doppler shift. A calibration method is disclosed wherein the amplifier gain and frequency counter trigger level are adjusted to achieve plateaus in the output of the frequency counter and thereby allow calibration without the necessity of being able to visually observe the flow.

  3. Evaluation of Cloud Type Occurrences and Radiative Forcings Simulated by a Cloud Resolving Model Using Observations from Sa...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cloud Type Occurrences and Radiative Forcings Simulated by a Cloud Resolving Model Using Observations from Satellite and Cloud Radar Y. Luo and S. K. Krueger University of Utah Salt Lake City, Utah Introduction Because of both the various effects clouds exert on the earth-atmospheric system and the cloud feedback, correct representations of clouds in numerical models are critical for accurate climate modeling and weather forecast. Unfortunately, determination of clouds and their radiative

  4. Science Goals for the ARM Recovery Act Radars

    SciTech Connect (OSTI)

    JH Mather

    2012-05-29

    Science Goals for the ARM Recovery Act Radars. In October 2008, an ARM workshop brought together approximately 30 climate research scientists to discuss the Atmospheric Radiation Measurement (ARM) Climate Research Facility's role in solving outstanding climate science issues. Through this discussion it was noted that one of ARM's primary contributions is to provide detailed information about cloud profiles and their impact on radiative fluxes. This work supports cloud parameterization development and improved understanding of cloud processes necessary for that development. A critical part of this work is measuring microphysical properties (cloud ice and liquid water content, cloud particle sizes, shapes, and distribution). ARM measurements and research have long included an emphasis on obtaining the best possible microphysical parameters with the available instrumentation. At the time of the workshop, this research was reaching the point where additional reduction in uncertainties in these critical parameters required new instrumentation for applications such as specifying radiative heating profiles, measuring vertical velocities, and studying the convective triggering and evolution of three-dimensional (3D) cloud fields. ARM was already operating a subset of the necessary instrumentation to make some progress on these problems; each of the ARM sites included (and still includes) a cloud radar (operating at 35 or 94 GHz), a cloud lidar, and balloon-borne temperature and humidity sensors. However, these measurements were inadequate for determining detailed microphysical properties in most cases. Additional instrumentation needed to improve retrievals of microphysical processes includes radars at two additional frequencies for a total of three at a single site (35 GHz, 94 GHz, and a precipitation radar) and a Doppler lidar. Evolving to a multi-frequency scanning radar is a medium-term goal to bridge our understanding of two-dimensional (2D) retrievals to the 3D cloud field. These additional microphysical measurements would allow detailed cloud properties to be derived even in the presence of light precipitation. It is important to couple these detailed measurements of cloud microphysics to vertical motion on the cloud scale to couple microphysics with meteorological processes. Vertically pointing Doppler radars provide the vertical motion of cloud particles but, to separate particle motion from air motion, a wind profiler is required. The American Recovery and Reinvestment Act provided the means to address these needs and implement a multi-frequency suite of radars, including scanning radars, at each of the ARM sites. In addition, Doppler lidars have been deployed at several sites. With these new measurement capabilities, ARM has the measurement capabilities to tackle the problems of improving microphysical profile descriptions and evaluating the relationship between our current narrow-field-of view, zenith perspective on clouds to a description of the full 3D cloud field and its temporal evolution.

  5. Developing and Evaluating Ice Cloud Parameterizations by

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    by remote sensing is that the transfer functions which relate the observables (e. g., radar Doppler spectrum) to cloud properties (e. g., ice water content, or IWC) are not...

  6. Parameterizing Size Distribution in Ice Clouds

    SciTech Connect (OSTI)

    DeSlover, Daniel; Mitchell, David L.

    2009-09-25

    PARAMETERIZING SIZE DISTRIBUTIONS IN ICE CLOUDS David L. Mitchell and Daniel H. DeSlover ABSTRACT An outstanding problem that contributes considerable uncertainty to Global Climate Model (GCM) predictions of future climate is the characterization of ice particle sizes in cirrus clouds. Recent parameterizations of ice cloud effective diameter differ by a factor of three, which, for overcast conditions, often translate to changes in outgoing longwave radiation (OLR) of 55 W m-2 or more. Much of this uncertainty in cirrus particle sizes is related to the problem of ice particle shattering during in situ sampling of the ice particle size distribution (PSD). Ice particles often shatter into many smaller ice fragments upon collision with the rim of the probe inlet tube. These small ice artifacts are counted as real ice crystals, resulting in anomalously high concentrations of small ice crystals (D < 100 m) and underestimates of the mean and effective size of the PSD. Half of the cirrus cloud optical depth calculated from these in situ measurements can be due to this shattering phenomenon. Another challenge is the determination of ice and liquid water amounts in mixed phase clouds. Mixed phase clouds in the Arctic contain mostly liquid water, and the presence of ice is important for determining their lifecycle. Colder high clouds between -20 and -36 oC may also be mixed phase but in this case their condensate is mostly ice with low levels of liquid water. Rather than affecting their lifecycle, the presence of liquid dramatically affects the cloud optical properties, which affects cloud-climate feedback processes in GCMs. This project has made advancements in solving both of these problems. Regarding the first problem, PSD in ice clouds are uncertain due to the inability to reliably measure the concentrations of the smallest crystals (D < 100 m), known as the small mode. Rather than using in situ probe measurements aboard aircraft, we employed a treatment of ice cloud optical properties formulated in terms of PSD parameters in combination with remote measurements of thermal radiances to characterize the small mode. This is possible since the absorption efficiency (Qabs) of small mode crystals is larger at 12 m wavelength relative to 11 m wavelength due to the process of wave resonance or photon tunneling more active at 12 m. This makes the 12/11 m absorption optical depth ratio (or equivalently the 12/11 m Qabs ratio) a means for detecting the relative concentration of small ice particles in cirrus. Using this principle, this project tested and developed PSD schemes that can help characterize cirrus clouds at each of the three ARM sites: SGP, NSA and TWP. This was the main effort of this project. These PSD schemes and ice sedimentation velocities predicted from them have been used to test the new cirrus microphysics parameterization in the GCM known as the Community Climate Systems Model (CCSM) as part of an ongoing collaboration with NCAR. Regarding the second problem, we developed and did preliminary testing on a passive thermal method for retrieving the total water path (TWP) of Arctic mixed phase clouds where TWPs are often in the range of 20 to 130 g m-2 (difficult for microwave radiometers to accurately measure). We also developed a new radar method for retrieving the cloud ice water content (IWC), which can be vertically integrated to yield the ice water path (IWP). These techniques were combined to determine the IWP and liquid water path (LWP) in Arctic clouds, and hence the fraction of ice and liquid water. We have tested this approach using a case study from the ARM field campaign called M-PACE (Mixed-Phase Arctic Cloud Experiment). This research led to a new satellite remote sensing method that appears promising for detecting low levels of liquid water in high clouds typically between -20 and -36 oC. We hope to develop this method in future research.

  7. Understanding Ice Supersaturation, Particle Growth, and Number Concentration in Cirrus Clouds

    SciTech Connect (OSTI)

    Comstock, Jennifer M.; Lin, Ruei-Fong; Starr, David O.; Yang, P.

    2008-12-10

    Many factors control the ice supersaturation and microphysical properties in cirrus clouds. We explore the effects of dynamic forcing, ice nucleation mechanisms, and ice crystal growth rate on the evolution and distribution of water vapor and cloud properties in cirrus clouds using a detailed microphysical model and remote sensing measurements obtained at the Department of Energys Atmospheric Radiation Measurement (ARM) Climate Research Facility located near Lamont, OK. To help understand dynamic scales important in cirrus formation, we force the model using both large-scale forcing derived using ARM variational analysis, and mean mesoscale velocity derived from radar Doppler velocity measurements. Both heterogeneous and homogeneous nucleation processes are explored, where we have implemented a rigorous classical theory heterogeneous nucleation scheme to compare with empirical representations. We evaluate model simulations by examining both bulk cloud properties and distributions of measured radar reflectivity, lidar extinction, and water vapor profiles, as well as retrieved cloud microphysical properties. This approach allows for independent verification of both the large and small particle modes of the particle size distribution. Our results suggest that mesoscale variability is the primary mechanism needed to reproduce observed quantities, while nucleation mechanism is secondary. Slow ice crystal growth tends to overestimate the number of small ice crystals, but does not seem to influence bulk properties such as ice water path and cloud thickness. The most realistic simulations as compared with observations are forced using mesoscale waves, include fast ice crystal growth, and initiate ice by either homogeneous or heterogeneous nucleation. Ice crystal number concentrations on the order of 10-100 L-1 produce results consistent with both lidar and radar observations during a cirrus event observed on 7 December 1999, which has an optical depth range typical of midlatitude cirrus.

  8. Determination of 3-D Cloud Ice Water Contents by Combining Multiple Data

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Sources from Satellite, Ground Radar, and a Numerical Model Determination of 3-D Cloud Ice Water Contents by Combining Multiple Data Sources from Satellite, Ground Radar, and a Numerical Model Liu, Guosheng Florida State University Seo, Eun-Kyoung Florida State University Category: Cloud Properties This study aims at determining the 3-dimensional distribution of ice water content over a broad area near the Atmospheric Radiation Measurement Southern Great Plain site, where cloud radar and

  9. Simulating Arctic mixed-phase clouds: Sensitivity to environmental

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    conditions and cloud microphysics processes Simulating Arctic mixed-phase clouds: Sensitivity to environmental conditions and cloud microphysics processes Sednev, Igor Lawrence Berkeley National Laboratory Menon, Surabi Lawrence Berkeley National Laboratory McFarquhar, Greg University of Illinois Category: Field Campaigns The importance of Arctic mixed-phase clouds on radiation and the Arctic climate are evaluated using the NASA GISS single column model (SCM) and cloud microphysics and radar

  10. The lidar dark band: An oddity of the radar bright band analogy

    SciTech Connect (OSTI)

    Sassen, K.

    1996-04-01

    Although much has sbeen learned from independent radar and lidar studies of atmospheric precipitations, occasionally supported by aircraft profiling, what has been lacking is combined optical, microwave, and insitu observations of the melting layer. Fortunately, the rainshowers on April 21, 1994, during the Remote Cloud Sensing intensive obervations Period (RCSIOP) at the Southern Great Plains Cloud and radiation Testbed (CART) site provided an opportunity for coordinated dual-wavelength University of Utah Polarization Diversity Lidar, University of Massachusetts Cloud Profiling Radar System Doppler Radar, and the University of North Dakota Citation aircraft measurements.

  11. Using Doppler spectra to separate hydrometeor populations and analyze ice precipitation in multilayered mixed-phase clouds

    SciTech Connect (OSTI)

    Rambukkange, Mahlon P.; Verlinde, J.; Eloranta, E. W.; Flynn, Connor J.; Clothiaux, Eugene E.

    2011-01-31

    Multimodality of cloud radar Doppler spectra is used to partition cloud particle phases and to separate distinct ice populations in the radar sample volume, thereby facilitating analysis of individual ice showers in multilayered mixed-phase clouds. A 35-GHz cloud radar located at Barrow, Alaska, during the Mixed-Phase Arctic Cloud Experiment collected the Doppler spectra. Data from a pair of collocated depolarization lidars confirmed the presence of two liquid cloud layers reported in this study. Surprisingly, both of these cloud layers were embedded in ice precipitation yet maintained their liquid. Our spectral separation of the ice precipitation yielded two distinct ice populations: ice initiated within the two liquid cloud layers and ice precipitation formed in higher cloud layers. Comparisons of ice fall velocity versus radar reflectivity relationships derived for distinct showers reveal that a single relationship might not properly represent the ice showers during this period.

  12. ARSCL Cloud Statistics - A Value-Added Product

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ARSCL Cloud Statistics - A Value-Added Product Y. Shi Pacific Northwest National Laboratory Richland, Washington M. A. Miller Brookhaven National Laboratory Upton, New York Introduction The active remote sensing of cloud layers (ARSCLs) value-added product (VAP) combines data from active remote sensors to produce an objective determination of cloud location, radar reflectivity, vertical velocity, and Doppler spectral width. Information about the liquid water path (LWP) in these clouds and the

  13. ARM Scanning Radar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (fixed elevation) 3. Sector scan (for cloud tracking) 4. Staring mode 3D-Cloud Products Case Study - Marine Stratocumulus 75 o Horizontal Wind Height In-cloud horizontal wind and...

  14. Continuous Profiles of Cloud Microphysical Properties for the Fixed Atmospheric Radiation Measurement Sites

    SciTech Connect (OSTI)

    Jensen, M; Jensen, K

    2006-06-01

    The Atmospheric Radiation Measurement (ARM) Program defined a specific metric for the third quarter of Fiscal Year 2006 to produce and refine a one-year continuous time series of cloud microphysical properties based on cloud radar measurements for each of the fixed ARM sites. To accomplish this metric, we used a combination of recently developed algorithms that interpret radar reflectivity profiles, lidar backscatter profiles, and microwave brightness temperatures into the context of the underlying cloud microphysical structure.

  15. A Method for the Automatic Detection of Insect Clutter in Doppler-Radar Returns.

    SciTech Connect (OSTI)

    Luke,E.; Kollias, P.; Johnson, K.

    2006-06-12

    The accurate detection and removal of insect clutter from millimeter wavelength cloud radar (MMCR) returns is of high importance to boundary layer cloud research (e.g., Geerts et al., 2005). When only radar Doppler moments are available, it is difficult to produce a reliable screening of insect clutter from cloud returns because their distributions overlap. Hence, screening of MMCR insect clutter has historically involved a laborious manual process of cross-referencing radar moments against measurements from other collocated instruments, such as lidar. Our study looks beyond traditional radar moments to ask whether analysis of recorded Doppler spectra can serve as the basis for reliable, automatic insect clutter screening. We focus on the MMCR operated by the Department of Energy's (DOE) Atmospheric Radiation Measurement (ARM) program at its Southern Great Plains (SGP) facility in Oklahoma. Here, archiving of full Doppler spectra began in September 2003, and during the warmer months, a pronounced insect presence regularly introduces clutter into boundary layer returns.

  16. Cloud Properties and Radiative Heating Rates for TWP

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Comstock, Jennifer

    2013-11-07

    A cloud properties and radiative heating rates dataset is presented where cloud properties retrieved using lidar and radar observations are input into a radiative transfer model to compute radiative fluxes and heating rates at three ARM sites located in the Tropical Western Pacific (TWP) region. The cloud properties retrieval is a conditional retrieval that applies various retrieval techniques depending on the available data, that is if lidar, radar or both instruments detect cloud. This Combined Remote Sensor Retrieval Algorithm (CombRet) produces vertical profiles of liquid or ice water content (LWC or IWC), droplet effective radius (re), ice crystal generalized effective size (Dge), cloud phase, and cloud boundaries. The algorithm was compared with 3 other independent algorithms to help estimate the uncertainty in the cloud properties, fluxes, and heating rates (Comstock et al. 2013). The dataset is provided at 2 min temporal and 90 m vertical resolution. The current dataset is applied to time periods when the MMCR (Millimeter Cloud Radar) version of the ARSCL (Active Remotely-Sensed Cloud Locations) Value Added Product (VAP) is available. The MERGESONDE VAP is utilized where temperature and humidity profiles are required. Future additions to this dataset will utilize the new KAZR instrument and its associated VAPs.

  17. Cloud Properties and Radiative Heating Rates for TWP

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Comstock, Jennifer

    A cloud properties and radiative heating rates dataset is presented where cloud properties retrieved using lidar and radar observations are input into a radiative transfer model to compute radiative fluxes and heating rates at three ARM sites located in the Tropical Western Pacific (TWP) region. The cloud properties retrieval is a conditional retrieval that applies various retrieval techniques depending on the available data, that is if lidar, radar or both instruments detect cloud. This Combined Remote Sensor Retrieval Algorithm (CombRet) produces vertical profiles of liquid or ice water content (LWC or IWC), droplet effective radius (re), ice crystal generalized effective size (Dge), cloud phase, and cloud boundaries. The algorithm was compared with 3 other independent algorithms to help estimate the uncertainty in the cloud properties, fluxes, and heating rates (Comstock et al. 2013). The dataset is provided at 2 min temporal and 90 m vertical resolution. The current dataset is applied to time periods when the MMCR (Millimeter Cloud Radar) version of the ARSCL (Active Remotely-Sensed Cloud Locations) Value Added Product (VAP) is available. The MERGESONDE VAP is utilized where temperature and humidity profiles are required. Future additions to this dataset will utilize the new KAZR instrument and its associated VAPs.

  18. Evaluation of high-level clouds in cloud resolving model simulations with ARM and KWAJEX observations

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Zheng; Muhlbauer, Andreas; Ackerman, Thomas

    2015-11-05

    In this paper, we evaluate high-level clouds in a cloud resolving model during two convective cases, ARM9707 and KWAJEX. The simulated joint histograms of cloud occurrence and radar reflectivity compare well with cloud radar and satellite observations when using a two-moment microphysics scheme. However, simulations performed with a single moment microphysical scheme exhibit low biases of approximately 20 dB. During convective events, two-moment microphysical overestimate the amount of high-level cloud and one-moment microphysics precipitate too readily and underestimate the amount and height of high-level cloud. For ARM9707, persistent large positive biases in high-level cloud are found, which are not sensitivemore » to changes in ice particle fall velocity and ice nuclei number concentration in the two-moment microphysics. These biases are caused by biases in large-scale forcing and maintained by the periodic lateral boundary conditions. The combined effects include significant biases in high-level cloud amount, radiation, and high sensitivity of cloud amount to nudging time scale in both convective cases. The high sensitivity of high-level cloud amount to the thermodynamic nudging time scale suggests that thermodynamic nudging can be a powerful ‘‘tuning’’ parameter for the simulated cloud and radiation but should be applied with caution. The role of the periodic lateral boundary conditions in reinforcing the biases in cloud and radiation suggests that reducing the uncertainty in the large-scale forcing in high levels is important for similar convective cases and has far reaching implications for simulating high-level clouds in super-parameterized global climate models such as the multiscale modeling framework.« less

  19. ARM - Measurement - Cloud size

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    measurements as cloud thickness, cloud area, and cloud aspect ratio. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the...

  20. Downhole pulse radar

    DOE Patents [OSTI]

    Chang, Hsi-Tien

    1987-09-28

    A borehole logging tool generates a fast rise-time, short duration, high peak-power radar pulse having broad energy distribution between 30 MHz and 300 MHz through a directional transmitting and receiving antennas having barium titanate in the electromagnetically active region to reduce the wavelength to within an order of magnitude of the diameter of the antenna. Radar returns from geological discontinuities are sampled for transmission uphole. 7 figs.

  1. Downhole pulse radar

    DOE Patents [OSTI]

    Chang, Hsi-Tien (Albuquerque, NM)

    1989-01-01

    A borehole logging tool generates a fast rise-time, short duration, high peak-power radar pulse having broad energy distribution between 30 MHz and 300 MHz through a directional transmitting and receiving antennas having barium titanate in the electromagnetically active region to reduce the wavelength to within an order of magnitude of the diameter of the antenna. Radar returns from geological discontinuities are sampled for transmission uphole.

  2. Stratiform and Convective Precipitation Observed by Multiple Radars during the DYNAMO/AMIE Experiment

    SciTech Connect (OSTI)

    Deng, Min; Kollias, Pavlos; Feng, Zhe; Zhang, Chidong; Long, Charles N.; Kalesse, Heike; Chandra, Arunchandra; Kumar, Vickal; Protat, Alain

    2014-11-01

    The motivation for this research is to develop a precipitation classification and rain rate estimation method using cloud radar-only measurements for Atmospheric Radiation Measurement (ARM) long-term cloud observation analysis, which are crucial and unique for studying cloud lifecycle and precipitation features under different weather and climate regimes. Based on simultaneous and collocated observations of the Ka-band ARM zenith radar (KAZR), two precipitation radars (NCAR S-PolKa and Texas A&M University SMART-R), and surface precipitation during the DYNAMO/AMIE field campaign, a new cloud radar-only based precipitation classification and rain rate estimation method has been developed and evaluated. The resulting precipitation classification is equivalent to those collocated SMART-R and S-PolKa observations. Both cloud and precipitation radars detected about 5% precipitation occurrence during this period. The convective (stratiform) precipitation fraction is about 18% (82%). The 2-day collocated disdrometer observations show an increased number concentration of large raindrops in convective rain compared to dominant concentration of small raindrops in stratiform rain. The composite distributions of KAZR reflectivity and Doppler velocity also show two distinct structures for convective and stratiform rain. These indicate that the method produces physically consistent results for two types of rain. The cloud radar-only rainfall estimation is developed based on the gradient of accumulative radar reflectivity below 1 km, near-surface Ze, and collocated surface rainfall (R) measurement. The parameterization is compared with the Z-R exponential relation. The relative difference between estimated and surface measured rainfall rate shows that the two-parameter relation can improve rainfall estimation.

  3. Precipitating clouds

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    processes, especially related ice. * Very large differences between observed IN number concentration and ice concentration in a given clouds. * Many ice nucleation modes are...

  4. ARM - Measurement - Radar reflectivity

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    upon the size, shape, aspect, and dielectric properties of that target. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the...

  5. Ground-Based Radar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The Atmospheric Radiation Measurement (ARM) Program A Laboratory for the Study of Clouds ... Tom Ackerman Chief Scientist ARM ARM Atmospheric Radiation Measurement Atmospheric ...

  6. ARM - Field Campaign - Remote Cloud Sensing (RCS) Field Evaluation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govCampaignsRemote Cloud Sensing (RCS) Field Evaluation ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Remote Cloud Sensing (RCS) Field Evaluation 1994.04.01 - 1994.05.31 Lead Scientist : Robert Kropfli Data Availability CPRS Cloud Data (from the University of Massachusetts Cloud Profiling Radar System (CPRS)) For data sets, see below. Abstract The primary purpose of the field evaluation and calibration

  7. ARM - Field Campaign - Remote Cloud Sensing (RCS) Field Evaluation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govCampaignsRemote Cloud Sensing (RCS) Field Evaluation ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Remote Cloud Sensing (RCS) Field Evaluation 1995.04.01 - 1995.05.31 Lead Scientist : Robert Kropfli Data Availability CPRS Cloud Data (from the University of Massachusetts Cloud Profiling Radar System (CPRS)) For data sets, see below. Abstract The primary purpose of the field evaluation and calibration

  8. Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Shupe, Matthew

    2013-05-22

    Time-height fields of retrieved in-cloud vertical wind velocity and turbulent dissipation rate, both retrieved primarily from vertically-pointing, Ka-band cloud radar measurements. Files are available for manually-selected, stratiform, mixed-phase cloud cases observed at the North Slope of Alaska (NSA) site during periods covering the Mixed-Phase Arctic Cloud Experiment (MPACE, late September through early November 2004) and the Indirect and Semi-Direct Aerosol Campaign (ISDAC, April-early May 2008). These time periods will be expanded in a future submission.

  9. Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Shupe, Matthew

    Time-height fields of retrieved in-cloud vertical wind velocity and turbulent dissipation rate, both retrieved primarily from vertically-pointing, Ka-band cloud radar measurements. Files are available for manually-selected, stratiform, mixed-phase cloud cases observed at the North Slope of Alaska (NSA) site during periods covering the Mixed-Phase Arctic Cloud Experiment (MPACE, late September through early November 2004) and the Indirect and Semi-Direct Aerosol Campaign (ISDAC, April-early May 2008). These time periods will be expanded in a future submission.

  10. Forthcoming Upgrades to the ARM MMCRs: Improved Radar Processor and Dual-Polarization

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Forthcoming Upgrades to the ARM MMCRs: Improved Radar Processor and Dual-Polarization K. P. Moran, B. E. Martner, and K. A. Clark National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado C. Chanders Science and Technology Corporation Background The Atmospheric Radiation Measurement (ARM) Millimeter Wavelength Cloud Radars (MMCRs) are vertically pointing ground-based Doppler systems, designed for long-term, unattended operations. In spite of very low

  11. ARM - Evaluation Product - Cloud Microbase-kazr Profiles (ka) VAP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ProductsCloud Microbase-kazr Profiles (ka) VAP ARM Data Discovery Browse Data Documentation Use the Data File Inventory tool to view data availability at the file level. Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Evaluation Product : Cloud Microbase-kazr Profiles (ka) VAP The KAZR radars have recently replaced the MMCR at ARM sites, and so the new KAZR-based radar products will now serve as input to Microbase. All of the historic Microbase

  12. SGP and TWP (Manus) Ice Cloud Vertical Velocities

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kalesse, Heike

    Daily netcdf-files of ice-cloud dynamics observed at the ARM sites at SGP (Jan1997-Dec2010) and Manus (Jul1999-Dec2010). The files include variables at different time resolution (10s, 20min, 1hr). Profiles of radar reflectivity factor (dbz), Doppler velocity (vel) as well as retrieved vertical air motion (V_air) and reflectivity-weighted particle terminal fall velocity (V_ter) are given at 10s, 20min and 1hr resolution. Retrieved V_air and V_ter follow radar notation, so positive values indicate downward motion. Lower level clouds are removed, however a multi-layer flag is included.

  13. SGP and TWP (Manus) Ice Cloud Vertical Velocities

    SciTech Connect (OSTI)

    Kalesse, Heike

    2013-06-27

    Daily netcdf-files of ice-cloud dynamics observed at the ARM sites at SGP (Jan1997-Dec2010) and Manus (Jul1999-Dec2010). The files include variables at different time resolution (10s, 20min, 1hr). Profiles of radar reflectivity factor (dbz), Doppler velocity (vel) as well as retrieved vertical air motion (V_air) and reflectivity-weighted particle terminal fall velocity (V_ter) are given at 10s, 20min and 1hr resolution. Retrieved V_air and V_ter follow radar notation, so positive values indicate downward motion. Lower level clouds are removed, however a multi-layer flag is included.

  14. Impulse radar studfinder

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1995-01-01

    An impulse radar studfinder propagates electromagnetic pulses and detects reflected pulses from a fixed range. Unmodulated pulses, about 200 ps wide, are emitted. A large number of reflected pulses are sampled and averaged. Background reflections are subtracted. Reflections from wall studs or other hidden objects are detected and displayed using light emitting diodes.

  15. Impulse radar studfinder

    DOE Patents [OSTI]

    McEwan, T.E.

    1995-10-10

    An impulse radar studfinder propagates electromagnetic pulses and detects reflected pulses from a fixed range. Unmodulated pulses, about 200 ps wide, are emitted. A large number of reflected pulses are sampled and averaged. Background reflections are subtracted. Reflections from wall studs or other hidden objects are detected and displayed using light emitting diodes. 9 figs.

  16. ARM - Measurement - Cloud type

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Measurement : Cloud type Cloud type such as cirrus, stratus, cumulus etc Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the...

  17. Just where exactly is the radar? (a.k.a. the radar antenna phase...

    Office of Scientific and Technical Information (OSTI)

    Just where exactly is the radar? (a.k.a. the radar antenna phase center). Citation Details In-Document Search Title: Just where exactly is the radar? (a.k.a. the radar antenna...

  18. TTU Advanced Doppler Radar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    TTU Advanced Doppler Radar - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Fuel Cycle Defense Waste Management Programs

  19. Radar Friendly Blades

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Radar Friendly Blades - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Fuel Cycle Defense Waste Management Programs Advanced

  20. Imaging synthetic aperture radar

    DOE Patents [OSTI]

    Burns, Bryan L.; Cordaro, J. Thomas

    1997-01-01

    A linear-FM SAR imaging radar method and apparatus to produce a real-time image by first arranging the returned signals into a plurality of subaperture arrays, the columns of each subaperture array having samples of dechirped baseband pulses, and further including a processing of each subaperture array to obtain coarse-resolution in azimuth, then fine-resolution in range, and lastly, to combine the processed subapertures to obtain the final fine-resolution in azimuth. Greater efficiency is achieved because both the transmitted signal and a local oscillator signal mixed with the returned signal can be varied on a pulse-to-pulse basis as a function of radar motion. Moreover, a novel circuit can adjust the sampling location and the A/D sample rate of the combined dechirped baseband signal which greatly reduces processing time and hardware. The processing steps include implementing a window function, stabilizing either a central reference point and/or all other points of a subaperture with respect to doppler frequency and/or range as a function of radar motion, sorting and compressing the signals using a standard fourier transforms. The stabilization of each processing part is accomplished with vector multiplication using waveforms generated as a function of radar motion wherein these waveforms may be synthesized in integrated circuits. Stabilization of range migration as a function of doppler frequency by simple vector multiplication is a particularly useful feature of the invention; as is stabilization of azimuth migration by correcting for spatially varying phase errors prior to the application of an autofocus process.

  1. Dispelling Clouds of Uncertainty

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lewis, Ernie; Teixeira, João

    2015-06-15

    How do you build a climate model that accounts for cloud physics and the transitions between cloud regimes? Use MAGIC.

  2. ER2 Instrumentation and Measurements for CLASIC (Cloud Land Surface Interaction Campaign) June-2007 SGP {Author-Jimmy Voyles}

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ER2 Desired Measurements for CLASIC June 2007 SGP May 31, 2007 1 MEASUREMENT SOURCE DESIRED MEASUREMENTS AND PRODUCTS INSTRUMENT SYSTEMS Cloud Radar System (CRS), W-Band (95 GHz) 1) Vertical profiles of calibrated radar reflectivity 2) Vertical profiles of Doppler velocity 3) Vertical profiles of estimated IWC 4) Vertical profiles of linear depolarization ratio 5) (ASCII files and quick look plots for all of the above quantities) Resolution: 5 sec resolution? Cloud Physics Lidar (CPL) (1064,

  3. Stratus Cloud Drizzle Retrieval During SHEBA from MMCR Doppler Moments

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Drizzle Retrieval During SHEBA from MMCR Doppler Moments A. S. Frisch National Oceanic and Atmospheric Administration Environmental Technology Laboratory Colorado State University Boulder, Colorado M. D. Shupe Science Technology Corporation National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado Introduction The National Oceanic and Atmospheric Administration/Environmental Technology Laboratory (NOAA/ETL) operated a 35-GHz cloud radar during the

  4. Global coherence of dust density waves

    SciTech Connect (OSTI)

    Killer, Carsten; Melzer, Andr

    2014-06-15

    The coherence of self-excited three-dimensional dust density waves has been experimentally investigated by comparing global and local wave properties. For that purpose, three-dimensional dust clouds have been confined in a radio frequency plasma with thermophoretic levitation. Global wave properties have been measured from the line-of-sight integrated dust density obtained from homogenous light extinction measurements. Local wave properties have been obtained from thin, two-dimensional illuminated laser slices of the cloud. By correlating the simultaneous global and local wave properties, the spatial coherence of the waves has been determined. We find that linear waves with small amplitudes tend to be fragmented, featuring an incoherent wave field. Strongly non-linear waves with large amplitudes, however, feature a strong spatial coherence throughout the dust cloud, indicating a high level of synchronization.

  5. Python-ARM Radar Toolkit

    Energy Science and Technology Software Center (OSTI)

    2013-03-17

    The Python-ARM Radar Toolkit (Py-ART) is a collection of radar quality control and retrieval codes which all work on two unifying Python objects: the PyRadar and PyGrid objects. By building ingests to several popular radar formats and then abstracting the interface Py-ART greatly simplifies data processing over several other available utilities. In addition Py-ART makes use of Numpy arrays as its primary storage mechanism enabling use of existing and extensive community software tools.

  6. ARM - Evaluation Product - KAZR Active Remotely-Sensed Cloud Locations

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (KAZRARSCL) Active Remotely-Sensed Cloud Locations (KAZRARSCL) ARM Data Discovery Browse Data Documentation Use the Data File Inventory tool to view data availability at the file level. Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Evaluation Product : KAZR Active Remotely-Sensed Cloud Locations (KAZRARSCL) [ ARM research - evaluation data product ] The KAZR-ARSCL VAP provides cloud boundaries and best-estimate time-height fields of radar

  7. Correcting radar range measurements for atmospheric propagation...

    Office of Scientific and Technical Information (OSTI)

    Correcting radar range measurements for atmospheric propagation effects. Citation Details In-Document Search Title: Correcting radar range measurements for atmospheric propagation...

  8. ARM - Radar Backgrounder

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    CenterRadar Backgrounder Media Contact Hanna Goss hanna-dot-goss-at-pnnl-dot-gov @armnewsteam Field Notes Blog Topics Field Notes107 AGU 3 AMIE 10 ARM Aerial Facility 2 ARM Mobile Facility 1 6 ARM Mobile Facility 2 47 ARM Mobile Facility 3 1 BAECC 1 BBOP 4 ENA 1 GOAMAZON 7 MAGIC 15 MC3E 17 PECAN 3 SGP 7 STORMVEX 29 TCAP 3 Search News Search Blog News Center All Categories What's this? Social Media Guidance News Center All Categories Features and Releases Facility News Field Notes Blog Events

  9. W-Band ARM Cloud Radar - Specifications and Design

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... computer with digital receiver. 6. Oscilloscope for monitoring detected RF signal. 7. Chiller for temperature stabilization of the RF unit. 8. Uninterruptible power supply (UPS). ...

  10. W-band ARM Cloud Radar (WACR) Update and Status

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    width) along with spectra data. The AMF WACR will be deployed with the AMF in Niamey, Niger early in 2006. We will present ingested WACR data formats available from the ARM...

  11. Algorithms for Filtering Insect Echoes from Cloud Radar Measurements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    M. Quante Institute for Coastal Research GKSS Research Center Geesthacht, Germany Introduction The Microwave Remote Sensing Laboratory (MIRSL) at the University of...

  12. Parameterization and analysis of 3-D radiative transfer in clouds

    SciTech Connect (OSTI)

    Varnai, Tamas

    2012-03-16

    This report provides a summary of major accomplishments from the project. The project examines the impact of radiative interactions between neighboring atmospheric columns, for example clouds scattering extra sunlight toward nearby clear areas. While most current cloud models donâ??t consider these interactions and instead treat sunlight in each atmospheric column separately, the resulting uncertainties have remained unknown. This project has provided the first estimates on the way average solar heating is affected by interactions between nearby columns. These estimates have been obtained by combining several years of cloud observations at three DOE Atmospheric Radiation Measurement (ARM) Climate Research Facility sites (in Alaska, Oklahoma, and Papua New Guinea) with simulations of solar radiation around the observed clouds. The importance of radiative interactions between atmospheric columns was evaluated by contrasting simulations that included the interactions with those that did not. This study provides lower-bound estimates for radiative interactions: It cannot consider interactions in cross-wind direction, because it uses two-dimensional vertical cross-sections through clouds that were observed by instruments looking straight up as clouds drifted aloft. Data from new DOE scanning radars will allow future radiative studies to consider the full three-dimensional nature of radiative processes. The results reveal that two-dimensional radiative interactions increase overall day-and-night average solar heating by about 0.3, 1.2, and 4.1 Watts per meter square at the three sites, respectively. This increase grows further if one considers that most large-domain cloud simulations have resolutions that cannot specify small-scale cloud variability. For example, the increases in solar heating mentioned above roughly double for a fairly typical model resolution of 1 km. The study also examined the factors that shape radiative interactions between atmospheric columns and found that local effects were often much larger than the overall values mentioned above, and were especially large for high sun and near convective clouds such as cumulus. The study also found that statistical methods such as neural networks appear promising for enabling cloud models to consider radiative interactions between nearby atmospheric columns. Finally, through collaboration with German scientists, the project found that new methods (especially one called â??stepwise krigingâ?) show great promise in filling gaps between cloud radar scans. If applied to data from the new DOE scanning cloud radars, these methods can yield large, continuous three-dimensional cloud structures for future radiative simulations.

  13. ARM Climate Research Facility Radar Operations Plan

    SciTech Connect (OSTI)

    Voyles, JW

    2012-05-18

    Roles, responsibilities, and processes associated with Atmospheric Radiation Measurement (ARM) Radar Operations.

  14. Multiwavelength observations of a devleoping cloud system: The FIRE II 26 November 1991 case study

    SciTech Connect (OSTI)

    Intrieri, J.M.; Eberhard, W.L.; Uttal, T.

    1995-12-01

    Simultaneous multiwavelength measurements of a developing cloud system were obtained by NOAA Doppler lidar, Doppler radar, Fourier transform infrared interferometer, and microwave and infrared radiometers on 26 November 1991. The evolution of the cloud system is described in terms of lidar backscatter, radar reflectivity and velocity, interferometer atmospheric spectra, and radiometer brightness temperature, integrated liquid water, and water vapor paths. Utilizing the difference in wavelength between the radar and lidar, and therefore their independent sensitivity to different regions of the same cloud, the cloud top, base, depth, and multiple layer heights can be determined with better accuracy than with either instrument alone. Combining the radar, lidar, and radiometer measurements using two different techniques allows an estimation of the vertical profile of cloud microphysical properties such as particle sizes. Enhancement of lidar backscatter near zenith revealed when highly oriented ice crystals were present. The authors demonstrate that no single instrument is sufficient to accurately describe cirrus clouds and that measurements in combination can provide important details on their geometric, radiative, and microphysical properties.

  15. Ocean current wave interaction study

    SciTech Connect (OSTI)

    Hayes, J.G.

    1980-09-20

    A numerical model has been developed to incorporate refraction of ocean surface gravity waves by major ocean currents. The model is initialized with directional wave spectra and verified with aircraft synthetic aperture radar X band spectra, laser profilometer spectra, and pitch and roll buoy data. Data collected during the Marineland test experiment are used as surface truth observations for the wave-current study. Evidence of Gulf Stream refraction and trapping of surface waves as well as caustics in the current is shown and modeled assuming a nonuniform Gulf Stream distribution. Frequency and directional resolution of the wave spectral distribution and the current refraction patterns illustrates the need for further study of ocean current-wave interaction in wave refraction studies.

  16. ARM - Measurement - Cloud location

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    point in space and time, typically expressed as a binary cloud mask. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the...

  17. ARM - Measurement - Cloud extinction

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    an incident beam by the process of cloud absorption andor scattering. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the...

  18. Dispelling Clouds of Uncertainty

    SciTech Connect (OSTI)

    Lewis, Ernie; Teixeira, João

    2015-06-15

    How do you build a climate model that accounts for cloud physics and the transitions between cloud regimes? Use MAGIC.

  19. Evaluation of Cloud-Resolving Model Intercomparison Simulations Using TWP-ICE Observations: Precipitation and Cloud Structure

    SciTech Connect (OSTI)

    Varble, Adam C.; Fridlind, Ann; Zipser, Ed; Ackerman, Andrew; Chaboureau, Jean-Pierre; Fan, Jiwen; Hill, Adrian; McFarlane, Sally A.; Pinty, Jean-Pierre; Shipway, Ben

    2011-06-24

    The Tropical Warm Pool - International Cloud Experiment (TWP-ICE) provided high quality model forcing and observational datasets through which detailed model and observational intercomparisons could be performed. In this first of a two part study, precipitation and cloud structures within nine cloud-resolving model simulations are compared with scanning radar reflectivity and satellite infrared brightness temperature observations during an active monsoon period from 19 to 25 January 2006. Most simulations slightly overestimate volumetric convective rainfall. Overestimation of simulated convective area by 50% or more in several simulations is somewhat offset by underestimation of mean convective rain rates. Stratiform volumetric rainfall is underestimated by 13% to 53% despite overestimation of stratiform area by up to 65% because stratiform rain rates in every simulation are much lower than observed. Although simulations match the peaked convective radar reflectivity distribution at low levels, they do not reproduce the peaked distributions observed above the melting level. Simulated radar reflectivity aloft in convective regions is too high in most simulations. 29 In stratiform regions, there is a large spread in model results with none resembling 30 observed distributions. Above the melting level, observed radar reflectivity decreases 31 more gradually with height than simulated radar reflectivity. A few simulations produce 32 unrealistically uniform and cold 10.8-?m infrared brightness temperatures, but several 33 simulations produce distributions close to observed. Assumed ice particle size 34 distributions appear to play a larger role than ice water contents in producing incorrect 35 simulated radar reflectivity distributions aloft despite substantial differences in mean 36 graupel and snow water contents across models. 37

  20. Evaluation of tropical cloud and precipitation statistics of CAM3 using CloudSat and CALIPSO data

    SciTech Connect (OSTI)

    Zhang, Y; Klein, S; Boyle, J; Mace, G G

    2008-11-20

    The combined CloudSat and CALIPSO satellite observations provide the first simultaneous measurements of cloud and precipitation vertical structure, and are used to examine the representation of tropical clouds and precipitation in the Community Atmosphere Model Version 3 (CAM3). A simulator package utilizing a model-to-satellite approach facilitates comparison of model simulations to observations, and a revised clustering method is used to sort the subgrid-scale patterns of clouds and precipitation into principal cloud regimes. Results from weather forecasts performed with CAM3 suggest that the model underestimates the horizontal extent of low and mid-level clouds in subsidence regions, but overestimates that of high clouds in ascending regions. CAM3 strongly overestimates the frequency of occurrence of the deep convection with heavy precipitation regime, but underestimates the horizontal extent of clouds and precipitation at low and middle levels when this regime occurs. This suggests that the model overestimates convective precipitation and underestimates stratiform precipitation consistent with a previous study that used only precipitation observations. Tropical cloud regimes are also evaluated in a different version of the model, CAM3.5, which uses a highly entraining plume in the parameterization of deep convection. While the frequency of occurrence of the deep convection with heavy precipitation regime from CAM3.5 forecasts decreases, the incidence of the low clouds with precipitation and congestus regimes increases. As a result, the parameterization change does not reduce the frequency of precipitating convection that is far too high relative to observations. For both versions of CAM, clouds and precipitation are overly reflective at the frequency of the CloudSat radar and thin clouds that could be detected by the lidar only are underestimated.

  1. Ground Penetrating Radar, Barrow, Alaska

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    John Peterson

    2015-03-06

    This is 500 MHz Ground Penetrating Radar collected along the AB Line in Intensive Site 1 beginning in October 2012 and collected along L2 in Intensive Site 0 beginning in September 2011. Both continue to the present.

  2. ARM - PI Product - Cloud Properties and Radiative Heating Rates for TWP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ProductsCloud Properties and Radiative Heating Rates for TWP ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Cloud Properties and Radiative Heating Rates for TWP A cloud properties and radiative heating rates dataset is presented where cloud properties retrieved using lidar and radar observations are input into a radiative transfer model to compute radiative fluxes and heating rates at three ARM sites

  3. ARM - PI Product - Cloud-Scale Vertical Velocity and Turbulent Dissipation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Rate Retrievals ProductsCloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals Time-height fields of retrieved in-cloud vertical wind velocity and turbulent dissipation rate, both retrieved primarily from vertically-pointing, Ka-band cloud radar measurements. Files

  4. Wide band stepped frequency ground penetrating radar

    DOE Patents [OSTI]

    Bashforth, M.B.; Gardner, D.; Patrick, D.; Lewallen, T.A.; Nammath, S.R.; Painter, K.D.; Vadnais, K.G.

    1996-03-12

    A wide band ground penetrating radar system is described embodying a method wherein a series of radio frequency signals is produced by a single radio frequency source and provided to a transmit antenna for transmission to a target and reflection therefrom to a receive antenna. A phase modulator modulates those portions of the radio frequency signals to be transmitted and the reflected modulated signal is combined in a mixer with the original radio frequency signal to produce a resultant signal which is demodulated to produce a series of direct current voltage signals, the envelope of which forms a cosine wave shaped plot which is processed by a Fast Fourier Transform Unit 44 into frequency domain data wherein the position of a preponderant frequency is indicative of distance to the target and magnitude is indicative of the signature of the target. 6 figs.

  5. Wide band stepped frequency ground penetrating radar

    DOE Patents [OSTI]

    Bashforth, Michael B.; Gardner, Duane; Patrick, Douglas; Lewallen, Tricia A.; Nammath, Sharyn R.; Painter, Kelly D.; Vadnais, Kenneth G.

    1996-01-01

    A wide band ground penetrating radar system (10) embodying a method wherein a series of radio frequency signals (60) is produced by a single radio frequency source (16) and provided to a transmit antenna (26) for transmission to a target (54) and reflection therefrom to a receive antenna (28). A phase modulator (18) modulates those portion of the radio frequency signals (62) to be transmitted and the reflected modulated signal (62) is combined in a mixer (34) with the original radio frequency signal (60) to produce a resultant signal (53) which is demodulated to produce a series of direct current voltage signals (66) the envelope of which forms a cosine wave shaped plot (68) which is processed by a Fast Fourier Transform unit 44 into frequency domain data (70) wherein the position of a preponderant frequency is indicative of distance to the target (54) and magnitude is indicative of the signature of the target (54).

  6. Wind Turbine Radar Interference Mitigation Working Group Releases...

    Energy Savers [EERE]

    Turbine Radar Interference Mitigation Working Group Releases New Report Wind Turbine Radar ... wind development to present challenges to radar missions is also likely to increase. ...

  7. X-band Scanning ARM Precipitation Radar (X-SAPR) Instrument Handbook

    SciTech Connect (OSTI)

    Widener, K; Bharadwaj, N

    2012-10-29

    The X-band scanning ARM cloud radar (X-SAPR) is a full-hemispherical scanning polarimetric Doppler radar transmitting simultaneously in both H and V polarizations. With a 200 kW magnetron transmitter, this puts 100 kW of transmitted power for each polarization. The receiver for the X-SAPR is a Vaisala Sigmet RVP-900 operating in a coherent-on-receive mode. Three X-SAPRs are deployed around the Southern Great Plains (SGP) Central Facility in a triangular array. A fourth X-SAPR is deployed near Barrow, Alaska on top of the Barrow Arctic Research Center.

  8. On the radar cross section (RCS) prediction of vehicles moving on the ground

    SciTech Connect (OSTI)

    Sabihi, Ahmad

    2014-12-10

    As readers should be aware, Radar Cross Section depends on the factors such as: Wave frequency and polarization, Target dimension, angle of ray incidence, Targets material and covering, Type of radar system as monostatic or bistatic, space in which contains target and propagating waves, and etc. Having moved or stationed in vehicles can be effective in RCS values. Here, we investigate effective factors in RCS of moving targets on the ground or sea. Image theory in electromagnetic applies to be taken into account RCS of a target over the ground or sea.

  9. ARM - Cloud Memory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Memory Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About ARM Global Warming FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans Cloud Memory Now you can make your own cloud memory game to practice recognizing clouds at home or share with your class. Example (not to scale) of cloud memory card available for download. Example (not to scale) of cloud memory card

  10. Merged and corrected 915 MHz Radar Wind Profiler moments

    SciTech Connect (OSTI)

    Jonathan Helmus,Virendra Ghate, Frederic Tridon

    2014-06-25

    The radar wind profiler (RWP) present at the SGP central facility operates at 915 MHz and was reconfigured in early 2011, to collect key sets of measurements for precipitation and boundary layer studies. The RWP is configured to run in two main operating modes: a precipitation (PR) mode with frequent vertical observations and a boundary layer (BL) mode that is similar to what has been traditionally applied to RWPs. To address issues regarding saturation of the radar signal, range resolution and maximum range, the RWP PR mode is set to operate with two different pulse lengths, termed as short pulse (SP) and long pulse (LP). Please refer to the RWP handbook (Coulter, 2012) for further information. Data from the RWP PR-SP and PR-LP modes have been extensively used to study deep precipitating clouds, especially their dynamical structure as the RWP data does not suffer from signal attenuation during these conditions (Giangrande et al., 2013). Tridon et al. (2013) used the data collected during the Mid-latitude Continental Convective Cloud Experiment (MC3E) to improve the estimation of noise floor of the RWP recorded Doppler spectra.

  11. A unified parameterization of clouds and turbulence using CLUBB and subcolumns in the Community Atmosphere Model

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Thayer-Calder, K.; Gettelman, A.; Craig, C.; Goldhaber, S.; Bogenschutz, P. A.; Chen, C.-C.; Morrison, H.; Höft, J.; Raut, E.; Griffin, B. M.; et al

    2015-06-30

    Most global climate models parameterize separate cloud types using separate parameterizations. This approach has several disadvantages, including obscure interactions between parameterizations and inaccurate triggering of cumulus parameterizations. Alternatively, a unified cloud parameterization uses one equation set to represent all cloud types. Such cloud types include stratiform liquid and ice cloud, shallow convective cloud, and deep convective cloud. Vital to the success of a unified parameterization is a general interface between clouds and microphysics. One such interface involves drawing Monte Carlo samples of subgrid variability of temperature, water vapor, cloud liquid, and cloud ice, and feeding the sample points into amore » microphysics scheme. This study evaluates a unified cloud parameterization and a Monte Carlo microphysics interface that has been implemented in the Community Atmosphere Model (CAM) version 5.3. Results describing the mean climate and tropical variability from global simulations are presented. The new model shows a degradation in precipitation skill but improvements in short-wave cloud forcing, liquid water path, long-wave cloud forcing, precipitable water, and tropical wave simulation. Also presented are estimations of computational expense and investigation of sensitivity to number of subcolumns.« less

  12. Use of the ARM Measurements of Spectral Zenith Radiance for Better Understanding of 3D Cloud-Radiation Processes & Aerosol-Cloud Interaction

    SciTech Connect (OSTI)

    Chiu, Jui-Yuan Christine

    2014-04-10

    This project focuses on cloud-radiation processes in a general three-dimensional cloud situation, with particular emphasis on cloud optical depth and effective particle size. The proposal has two main parts. Part one exploits the large number of new wavelengths offered by the Atmospheric Radiation Measurement (ARM) zenith-pointing ShortWave Spectrometer (SWS), to develop better retrievals not only of cloud optical depth but also of cloud particle size. We also take advantage of the SWS’ high sampling resolution to study the “twilight zone” around clouds where strong aerosol-cloud interactions are taking place. Part two involves continuing our cloud optical depth and cloud fraction retrieval research with ARM’s 2-channel narrow vield-of-view radiometer and sunphotometer instrument by, first, analyzing its data from the ARM Mobile Facility deployments, and second, making our algorithms part of ARM’s operational data processing.

  13. Obstacle penetrating dynamic radar imaging system

    DOE Patents [OSTI]

    Romero, Carlos E. (Livermore, CA); Zumstein, James E. (Livermore, CA); Chang, John T. (Danville, CA); Leach, Jr.. Richard R. (Castro Valley, CA)

    2006-12-12

    An obstacle penetrating dynamic radar imaging system for the detection, tracking, and imaging of an individual, animal, or object comprising a multiplicity of low power ultra wideband radar units that produce a set of return radar signals from the individual, animal, or object, and a processing system for said set of return radar signals for detection, tracking, and imaging of the individual, animal, or object. The system provides a radar video system for detecting and tracking an individual, animal, or object by producing a set of return radar signals from the individual, animal, or object with a multiplicity of low power ultra wideband radar units, and processing said set of return radar signals for detecting and tracking of the individual, animal, or object.

  14. How Radar Works | Open Energy Information

    Open Energy Info (EERE)

    Radar Works Jump to: navigation, search OpenEI Reference LibraryAdd to library Web Site: How Radar Works Author Institute For Geophysics Published Institute For Geophysics, 2013...

  15. GMTI radar minimum detectable velocity.

    SciTech Connect (OSTI)

    Richards, John Alfred

    2011-04-01

    Minimum detectable velocity (MDV) is a fundamental consideration for the design, implementation, and exploitation of ground moving-target indication (GMTI) radar imaging modes. All single-phase-center air-to-ground radars are characterized by an MDV, or a minimum radial velocity below which motion of a discrete nonstationary target is indistinguishable from the relative motion between the platform and the ground. Targets with radial velocities less than MDV are typically overwhelmed by endoclutter ground returns, and are thus not generally detectable. Targets with radial velocities greater than MDV typically produce distinct returns falling outside of the endoclutter ground returns, and are thus generally discernible using straightforward detection algorithms. This document provides a straightforward derivation of MDV for an air-to-ground single-phase-center GMTI radar operating in an arbitrary geometry.

  16. Radar operation in a hostile electromagnetic environment

    SciTech Connect (OSTI)

    Doerry, Armin Walter

    2014-03-01

    Radar ISR does not always involve cooperative or even friendly targets. An adversary has numerous techniques available to him to counter the effectiveness of a radar ISR sensor. These generally fall under the banner of jamming, spoofing, or otherwise interfering with the EM signals required by the radar sensor. Consequently mitigation techniques are prudent to retain efficacy of the radar sensor. We discuss in general terms a number of mitigation techniques.

  17. Fine-scale Horizontal Structure of Arctic Mixed-Phase Clouds.

    SciTech Connect (OSTI)

    Rambukkange,M.; Verlinde, J.; Elorante, E.; Luke, E.; Kollias, P.; Shupe, M.

    2006-07-10

    Recent in situ observations in stratiform clouds suggest that mixed phase regimes, here defined as limited cloud volumes containing both liquid and solid water, are constrained to narrow layers (order 100 m) separating all-liquid and fully glaciated volumes (Hallett and Viddaurre, 2005). The Department of Energy Atmospheric Radiation Measurement Program's (DOE-ARM, Ackerman and Stokes, 2003) North Slope of Alaska (NSA) ARM Climate Research Facility (ACRF) recently started collecting routine measurement of radar Doppler velocity power spectra from the Millimeter Cloud Radar (MMCR). Shupe et al. (2004) showed that Doppler spectra has potential to separate the contributions to the total reflectivity of the liquid and solid water in the radar volume, and thus to investigate further Hallett and Viddaurre's findings. The Mixed-Phase Arctic Cloud Experiment (MPACE) was conducted along the NSA to investigate the properties of Arctic mixed phase clouds (Verlinde et al., 2006). We present surface based remote sensing data from MPACE to discuss the fine-scale structure of the mixed-phase clouds observed during this experiment.

  18. Clouds, aerosol, and precipitation in the Marine Boundary Layer: An ARM mobile facility deployment

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wood, Robert; Luke, Ed; Wyant, Matthew; Bretherton, Christopher S.; Remillard, Jasmine; Kollias, Pavlos; Fletcher, Jennifer; Stemmler, Jayson; deSzoeke, S.; Yuter, Sandra; et al

    2014-04-27

    The Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) deployment at Graciosa Island in the Azores generated a 21-month (April 2009-December 2010) comprehensive dataset documenting clouds, aerosols, and precipitation using the Atmospheric Radiation Measurement Program (ARM) Mobile Facility (AMF). The scientific aim of the deployment is to gain improved understanding of the interactions of clouds, aerosols, and precipitation in the marine boundary layer. Graciosa Island straddles the boundary between the subtropics and midlatitudes in the Northeast Atlantic Ocean and consequently experiences a great diversity of meteorological and cloudiness conditions. Low clouds are the dominant cloud type, with stratocumulusmore » and cumulus occurring regularly. Approximately half of all clouds contained precipitation detectable as radar echoes below the cloud base. Radar and satellite observations show that clouds with tops from 1-11 km contribute more or less equally to surface-measured precipitation at Graciosa. A wide range of aerosol conditions was sampled during the deployment consistent with the diversity of sources as indicated by back-trajectory analysis. Preliminary findings suggest important two-way interactions between aerosols and clouds at Graciosa, with aerosols affecting light precipitation and cloud radiative properties while being controlled in part by precipitation scavenging.The data from Graciosa are being compared with short-range forecasts made with a variety of models. A pilot analysis with two climate and two weather forecast models shows that they reproduce the observed time-varying vertical structure of lower-tropospheric cloud fairly well but the cloud-nucleating aerosol concentrations less well. The Graciosa site has been chosen to be a permanent fixed ARM site that became operational in October 2013.« less

  19. Clouds, aerosol, and precipitation in the Marine Boundary Layer: An ARM mobile facility deployment

    SciTech Connect (OSTI)

    Wood, Robert; Luke, Ed; Wyant, Matthew; Bretherton, Christopher S.; Remillard, Jasmine; Kollias, Pavlos; Fletcher, Jennifer; Stemmler, Jayson; deSzoeke, S.; Yuter, Sandra; Miller, Matthew; Mechem, David; Tselioudis, George; Chiu, Christine; Mann, Julia; O Connor, Ewan; Hogan, Robin; Dong, Xiquan; Miller, Mark; Ghate, Virendra; Jefferson, Anne; Min, Qilong; Minnis, Patrick; Palinkonda, Rabindra; Albrecht, Bruce; Hannay, Cecile; Lin, Yanluan

    2014-04-27

    The Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) deployment at Graciosa Island in the Azores generated a 21-month (April 2009-December 2010) comprehensive dataset documenting clouds, aerosols, and precipitation using the Atmospheric Radiation Measurement Program (ARM) Mobile Facility (AMF). The scientific aim of the deployment is to gain improved understanding of the interactions of clouds, aerosols, and precipitation in the marine boundary layer. Graciosa Island straddles the boundary between the subtropics and midlatitudes in the Northeast Atlantic Ocean and consequently experiences a great diversity of meteorological and cloudiness conditions. Low clouds are the dominant cloud type, with stratocumulus and cumulus occurring regularly. Approximately half of all clouds contained precipitation detectable as radar echoes below the cloud base. Radar and satellite observations show that clouds with tops from 1-11 km contribute more or less equally to surface-measured precipitation at Graciosa. A wide range of aerosol conditions was sampled during the deployment consistent with the diversity of sources as indicated by back-trajectory analysis. Preliminary findings suggest important two-way interactions between aerosols and clouds at Graciosa, with aerosols affecting light precipitation and cloud radiative properties while being controlled in part by precipitation scavenging.The data from Graciosa are being compared with short-range forecasts made with a variety of models. A pilot analysis with two climate and two weather forecast models shows that they reproduce the observed time-varying vertical structure of lower-tropospheric cloud fairly well but the cloud-nucleating aerosol concentrations less well. The Graciosa site has been chosen to be a permanent fixed ARM site that became operational in October 2013.

  20. A unified parameterization of clouds and turbulence using CLUBB and subcolumns in the Community Atmosphere Model

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Thayer-Calder, K.; Gettelman, A.; Craig, C.; Goldhaber, S.; Bogenschutz, P. A.; Chen, C.-C.; Morrison, H.; Höft, J.; Raut, E.; Griffin, B. M.; et al

    2015-12-01

    Most global climate models parameterize separate cloud types using separate parameterizations. This approach has several disadvantages, including obscure interactions between parameterizations and inaccurate triggering of cumulus parameterizations. Alternatively, a unified cloud parameterization uses one equation set to represent all cloud types. Such cloud types include stratiform liquid and ice cloud, shallow convective cloud, and deep convective cloud. Vital to the success of a unified parameterization is a general interface between clouds and microphysics. One such interface involves drawing Monte Carlo samples of subgrid variability of temperature, water vapor, cloud liquid, and cloud ice, and feeding the sample points into amore » microphysics scheme. This study evaluates a unified cloud parameterization and a Monte Carlo microphysics interface that has been implemented in the Community Atmosphere Model (CAM) version 5.3. Model computational expense is estimated, and sensitivity to the number of subcolumns is investigated. Results describing the mean climate and tropical variability from global simulations are presented. The new model shows a degradation in precipitation skill but improvements in shortwave cloud forcing, liquid water path, long-wave cloud forcing, precipitable water, and tropical wave simulation.« less

  1. Two terminal micropower radar sensor

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1995-01-01

    A simple, low power ultra-wideband radar motion sensor/switch configuration connects a power source and load to ground. The switch is connected to and controlled by the signal output of a radar motion sensor. The power input of the motion sensor is connected to the load through a diode which conducts power to the motion sensor when the switch is open. A storage capacitor or rechargeable battery is connected to the power input of the motion sensor. The storage capacitor or battery is charged when the switch is open and powers the motion sensor when the switch is closed. The motion sensor and switch are connected between the same two terminals between the source/load and ground.

  2. Two terminal micropower radar sensor

    DOE Patents [OSTI]

    McEwan, T.E.

    1995-11-07

    A simple, low power ultra-wideband radar motion sensor/switch configuration connects a power source and load to ground. The switch is connected to and controlled by the signal output of a radar motion sensor. The power input of the motion sensor is connected to the load through a diode which conducts power to the motion sensor when the switch is open. A storage capacitor or rechargeable battery is connected to the power input of the motion sensor. The storage capacitor or battery is charged when the switch is open and powers the motion sensor when the switch is closed. The motion sensor and switch are connected between the same two terminals between the source/load and ground. 3 figs.

  3. Radar channel balancing with commutation

    SciTech Connect (OSTI)

    Doerry, Armin Walter

    2014-02-01

    When multiple channels are employed in a pulse-Doppler radar, achieving and maintaining balance between the channels is problematic. In some circumstances the channels may be commutated to achieve adequate balance. Commutation is the switching, trading, toggling, or multiplexing of the channels between signal paths. Commutation allows modulating the imbalance energy away from the balanced energy in Doppler, where it can be mitigated with filtering.

  4. Novel Use of P- and S-Wave Seismic Attenuation for Deep Natural...

    Office of Scientific and Technical Information (OSTI)

    Novel Use of P- and S-Wave Seismic Attenuation for Deep Natural Gas Exploration and ... Sponsoring Org: USDOE Country of Publication: United States Language: English Word Cloud ...

  5. PROGRESS REPORT OF FY 2004 ACTIVITIES: IMPROVED WATER VAPOR AND CLOUD RETRIEVALS AT THE NSA/AAO

    SciTech Connect (OSTI)

    E. R. Westwater; V. V. Leuskiy; M. Klein; A. J. Gasiewski; and J. A. Shaw

    2004-11-01

    The basic goals of the research are to develop and test algorithms and deploy instruments that improve measurements of water vapor, cloud liquid, and cloud coverage, with a focus on the Arctic conditions of cold temperatures and low concentrations of water vapor. The importance of accurate measurements of column amounts of water vapor and cloud liquid has been well documented by scientists within the Atmospheric Radiation Measurement Program. Although several technologies have been investigated to measure these column amounts, microwave radiometers (MWR) have been used operationally by the ARM program for passive retrievals of these quantities: precipitable water vapor (PWV) and integrated water liquid (IWL). The technology of PWV and IWL retrievals has advanced steadily since the basic 2-channel MWR was first deployed at ARM CART sites Important advances are the development and refinement of the tipcal calibration method [1,2], and improvement of forward model radiative transfer algorithms [3,4]. However, the concern still remains that current instruments deployed by ARM may be inadequate to measure low amounts of PWV and IWL. In the case of water vapor, this is especially important because of the possibility of scaling and/or quality control of radiosondes by the water amount. Extremely dry conditions, with PWV less than 3 mm, commonly occur in Polar Regions during the winter months. Accurate measurements of the PWV during such dry conditions are needed to improve our understanding of the regional radiation energy budgets. The results of a 1999 experiment conducted at the ARM North Slope of Alaska/Adjacent Arctic Ocean (NSA/AAO) site during March of 1999 [5] have shown that the strength associated with the 183 GHz water vapor absorption line makes radiometry in this frequency regime suitable for measuring low amounts of PWV. As a portion of our research, we conducted another millimeter wave radiometric experiment at the NSA/AAO in March-April 2004. This experiment relied heavily on our experiences of the 1999 experiment. Particular attention was paid to issues of radiometric calibration and radiosonde intercomparisons. Our theoretical and experimental work also supplements efforts by industry (F. Solheim, Private Communication) to develop sub-millimeter radiometers for ARM deployment. In addition to quantitative improvement of water vapor measurements at cold temperature, the impact of adding millimeter-wave window channels to improve the sensitivity to arctic clouds was studied. We also deployed an Infrared Cloud Imager (ICI) during this experiment, both for measuring continuous day-night statistics of the study of cloud coverage and identifying conditions suitable for tipcal analysis. This system provided the first capability of determining spatial cloud statistics continuously in both day and night at the NSA site and has been used to demonstrate that biases exist in inferring cloud statistics from either zenith-pointing active sensors (lidars or radars) or sky imagers that rely on scattered sunlight in daytime and star maps at night [6].

  6. 915-MHz Radar Wind Profiler (915RWP) Handbook

    SciTech Connect (OSTI)

    Coulter, R

    2005-01-01

    The 915 MHz radar wind profiler/radio acoustic sounding system (RWP/RASS) measures wind profiles and backscattered signal strength between (nominally) 0.1 km and 5 km and virtual temperature profiles between 0.1 km and 2.5 km. It operates by transmitting electromagnetic energy into the atmosphere and measuring the strength and frequency of backscattered energy. Virtual temperatures are recovered by transmitting an acoustic signal vertically and measuring the electromagnetic energy scattered from the acoustic wavefront. Because the propagation speed of the acoustic wave is proportional to the square root of the virtual temperature of the air, the virtual temperature can be recovered by measuring the Doppler shift of the scattered electromagnetic wave.

  7. Lightning and radar observations of hurricane Rita landfall

    SciTech Connect (OSTI)

    Henderson, Bradley G; Suszcynsky, David M; Hamlin, Timothy E; Jeffery, C A; Wiens, Kyle C; Orville, R E

    2009-01-01

    Los Alamos National Laboratory (LANL) owns and operates an array of Very-Low Frequency (VLF) sensors that measure the Radio-Frequency (RF) waveforms emitted by Cloud-to-Ground (CG) and InCloud (IC) lightning. This array, the Los Alamos Sferic Array (LASA), has approximately 15 sensors concentrated in the Great Plains and Florida, which detect electric field changes in a bandwidth from 200 Hz to 500 kHz (Smith et al., 2002). Recently, LANL has begun development of a new dual-band RF sensor array that includes the Very-High Frequency (VHF) band as well as the VLF. Whereas VLF lightning emissions can be used to deduce physical parameters such as lightning type and peak current, VHF emissions can be used to perform precise 3d mapping of individual radiation sources, which can number in the thousands for a typical CG flash. These new dual-band sensors will be used to monitor lightning activity in hurricanes in an effort to better predict intensification cycles. Although the new LANL dual-band array is not yet operational, we have begun initial work utilizing both VLF and VHF lightning data to monitor hurricane evolution. In this paper, we present the temporal evolution of Rita's landfall using VLF and VHF lightning data, and also WSR-88D radar. At landfall, Rita's northern eyewall experienced strong updrafts and significant lightning activity that appear to mark a transition between oceanic hurricane dynamics and continental thunderstorm dynamics. In section 2, we give a brief overview of Hurricane Rita, including its development as a hurricane and its lightning history. In the following section, we present WSR-88D data of Rita's landfall, including reflectivity images and temporal variation. In section 4, we present both VHF and VLF lightning data, overplotted on radar reflectivity images. Finally, we discuss our observations, including a comparison to previous studies and a brief conclusion.

  8. Synthetic Aperture Radar Persistent Scatterer Interferometry...

    Open Energy Info (EERE)

    NA, 2010 DOI Not Provided Check for DOI availability: http:crossref.org Online Internet link for Synthetic Aperture Radar Persistent Scatterer Interferometry (PSInSAR)...

  9. Ultra-wideband radar motion sensor

    DOE Patents [OSTI]

    McEwan, T.E.

    1994-11-01

    A motion sensor is based on ultra-wideband (UWB) radar. UWB radar range is determined by a pulse-echo interval. For motion detection, the sensors operate by staring at a fixed range and then sensing any change in the averaged radar reflectivity at that range. A sampling gate is opened at a fixed delay after the emission of a transmit pulse. The resultant sampling gate output is averaged over repeated pulses. Changes in the averaged sampling gate output represent changes in the radar reflectivity at a particular range, and thus motion. 15 figs.

  10. Sandia National Laboratories: Synthetic Aperture Radar (SAR)...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Synthetic Aperture Radar (SAR) Imagery The following is a selection of imagery available for your viewing, sorted by frequency band andor program. (Note: Resolutions are for...

  11. ARM - Measurement - Cloud fraction

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    fraction ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud fraction Fraction of sky covered by clouds. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance

  12. Radar network communication through sensing of frequency hopping

    DOE Patents [OSTI]

    Dowla, Farid; Nekoogar, Faranak

    2013-05-28

    In one embodiment, a radar communication system includes a plurality of radars having a communication range and being capable of operating at a sensing frequency and a reporting frequency, wherein the reporting frequency is different than the sensing frequency, each radar is adapted for operating at the sensing frequency until an event is detected, each radar in the plurality of radars has an identification/location frequency for reporting information different from the sensing frequency, a first radar of the radars which senses the event sends a reporting frequency corresponding to its identification/location frequency when the event is detected, and all other radars in the plurality of radars switch their reporting frequencies to match the reporting frequency of the first radar upon detecting the reporting frequency switch of a radar within the communication range. In another embodiment, a method is presented for communicating information in a radar system.

  13. Finance Idol Word Cloud

    Broader source: Energy.gov [DOE]

    This word cloud represents the topics discussed during the Big and Small Ideas: How to Lower Solar Financing Costs breakout session at the SunShot Grand Challenge.

  14. ARM - Measurement - Cloud phase

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    that involves property descriptors such as stratus, cumulus, and cirrus. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the...

  15. Comparison of Simulated and Observed Continental Tropical Anvil Clouds and Their Radiative Heating Profiles

    SciTech Connect (OSTI)

    Powell, Scott W.; Houze, R.; Kumar, Anil; McFarlane, Sally A.

    2012-09-06

    Vertically pointing millimeter-wavelength radar observations of anvil clouds extending from mesoscale convective systems (MCSs) that pass over an Atmospheric Radiation Measurement Program (ARM) field site in Niamey, Niger, are compared to anvil structures generated by the Weather Research and Forecasting (WRF) mesoscale model using six different microphysical schemes. The radar data provide the statistical distribution of the radar reflectivity values as a function of height and anvil thickness. These statistics are compared to the statistics of the modeled anvil cloud reflectivity at all altitudes. Requiring the model to be statistically accurate at all altitudes is a stringent test of the model performance. The typical vertical profile of radiative heating in the anvil clouds is computed from the radar observations. Variability of anvil structures from the different microphysical schemes provides an estimate of the inherent uncertainty in anvil radiative heating profiles. All schemes underestimate the optical thickness of thin anvils and cirrus, resulting in a bias of excessive net anvil heating in all of the simulations.

  16. Performance limits for maritime Inverse Synthetic Aperture Radar...

    Office of Scientific and Technical Information (OSTI)

    Performance limits for maritime Inverse Synthetic Aperture Radar (ISAR). Citation Details In-Document Search Title: Performance limits for maritime Inverse Synthetic Aperture Radar...

  17. INTERAGENCY FIELD TEST & EVALUATION OF WIND TURBINE - RADAR INTERFEREN...

    Office of Environmental Management (EM)

    INTERAGENCY FIELD TEST & EVALUATION OF WIND TURBINE - RADAR INTERFERENCE MITIGATION TECHNOLOGIES INTERAGENCY FIELD TEST & EVALUATION OF WIND TURBINE - RADAR INTERFERENCE MITIGATION ...

  18. Radar range measurements in the atmosphere. (Technical Report...

    Office of Scientific and Technical Information (OSTI)

    Radar range measurements in the atmosphere. Citation Details In-Document Search Title: Radar range measurements in the atmosphere. You are accessing a document from the...

  19. Radar range measurements in the atmosphere. (Technical Report...

    Office of Scientific and Technical Information (OSTI)

    Radar range measurements in the atmosphere. Citation Details In-Document Search Title: Radar range measurements in the atmosphere. The earth's atmosphere affects the velocity of...

  20. Ultra-wideband radar sensors and networks

    DOE Patents [OSTI]

    Leach, Jr., Richard R; Nekoogar, Faranak; Haugen, Peter C

    2013-08-06

    Ultra wideband radar motion sensors strategically placed in an area of interest communicate with a wireless ad hoc network to provide remote area surveillance. Swept range impulse radar and a heart and respiration monitor combined with the motion sensor further improves discrimination.

  1. Helicopter discrimination apparatus for the murine radar

    DOE Patents [OSTI]

    Webb, Jr., John G.; Gray, Roger M.

    1977-01-01

    A helicopter discrimination apparatus for a radar utilizing doppler filtering to discriminate between a missile and ground clutter. The short duration of the doppler filter pulses which are emitted by helicopter rotor blades are processed to prevent false alarms, thus allowing the radar-protected helicopter to operate in formation with other helicopters while maintaining protection against infra-red-seeking missiles.

  2. Boundary Layer Cloud Turbulence Characteristics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (10) Modeling Need (10) Cloud Boundaries 9 9 Cloud Fraction Variance Skewness UpDowndraft coverage Dominant Freq. signal Dissipation rate ??? Observation-Modeling Interface...

  3. ARM - Measurement - Cloud droplet size

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    droplet size Linear size (e.g. radius or diameter) of a cloud particle Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the...

  4. ARM - Measurement - Cloud effective radius

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the number size distribution of cloud particles, whether liquid or ice. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the...

  5. Cloud computing security.

    SciTech Connect (OSTI)

    Shin, Dongwan; Claycomb, William R.; Urias, Vincent E.

    2010-10-01

    Cloud computing is a paradigm rapidly being embraced by government and industry as a solution for cost-savings, scalability, and collaboration. While a multitude of applications and services are available commercially for cloud-based solutions, research in this area has yet to fully embrace the full spectrum of potential challenges facing cloud computing. This tutorial aims to provide researchers with a fundamental understanding of cloud computing, with the goals of identifying a broad range of potential research topics, and inspiring a new surge in research to address current issues. We will also discuss real implementations of research-oriented cloud computing systems for both academia and government, including configuration options, hardware issues, challenges, and solutions.

  6. Magneto-Radar Hidden Metal Detector

    DOE Patents [OSTI]

    McEwan, Thomas E. (Las Vegas, NV)

    2005-07-05

    A varying magnetic field excites slight vibrations in an object and a radar sensor detects the vibrations at a harmonic of the excitation frequency. The synergy of the magnetic excitation and radar detection provides increased detection range compared to conventional magnetic metal detectors. The radar rejects background clutter by responding only to reflecting objects that are vibrating at a harmonic excitation field, thereby significantly improving detection reliability. As an exemplary arrangement, an ultra-wideband micropower impulse radar (MIR) is capable of being employed to provide superior materials penetration while providing range information. The magneto-radar may be applied to pre-screening magnetic resonance imaging (MRI) patients, landmine detection and finding hidden treasures.

  7. Tangential velocity measurement using interferometric MTI radar

    DOE Patents [OSTI]

    Doerry, Armin W.; Mileshosky, Brian P.; Bickel, Douglas L.

    2006-01-03

    Radar systems use time delay measurements between a transmitted signal and its echo to calculate range to a target. Ranges that change with time cause a Doppler offset in phase and frequency of the echo. Consequently, the closing velocity between target and radar can be measured by measuring the Doppler offset of the echo. The closing velocity is also known as radial velocity, or line-of-sight velocity. Doppler frequency is measured in a pulse-Doppler radar as a linear phase shift over a set of radar pulses during some Coherent Processing Interval (CPI). An Interferometric Moving Target Indicator (MTI) radar can be used to measure the tangential velocity component of a moving target. Multiple baselines, along with the conventional radial velocity measurement, allow estimating the true 3-D velocity of a target.

  8. The Magellan Final Report on Cloud Computing

    SciTech Connect (OSTI)

    ,; Coghlan, Susan; Yelick, Katherine

    2011-12-21

    The goal of Magellan, a project funded through the U.S. Department of Energy (DOE) Office of Advanced Scientific Computing Research (ASCR), was to investigate the potential role of cloud computing in addressing the computing needs for the DOE Office of Science (SC), particularly related to serving the needs of mid- range computing and future data-intensive computing workloads. A set of research questions was formed to probe various aspects of cloud computing from performance, usability, and cost. To address these questions, a distributed testbed infrastructure was deployed at the Argonne Leadership Computing Facility (ALCF) and the National Energy Research Scientific Computing Center (NERSC). The testbed was designed to be flexible and capable enough to explore a variety of computing models and hardware design points in order to understand the impact for various scientific applications. During the project, the testbed also served as a valuable resource to application scientists. Applications from a diverse set of projects such as MG-RAST (a metagenomics analysis server), the Joint Genome Institute, the STAR experiment at the Relativistic Heavy Ion Collider, and the Laser Interferometer Gravitational Wave Observatory (LIGO), were used by the Magellan project for benchmarking within the cloud, but the project teams were also able to accomplish important production science utilizing the Magellan cloud resources.

  9. ARM - Cloud and Rain

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ListCloud and Rain Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About ARM Global Warming FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans Cloud and Rain Water vapor is an invisible gas that is always present in the troposphere. However, the amount of water vapor which the air can hold depends directly on the air temperature. Warm air can hold much more water

  10. Magellan: A Cloud Computing Testbed

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Magellan News & Announcements Archive Petascale Initiative Exascale Computing APEX Home » R & D » Archive » Magellan: A Cloud Computing Testbed Magellan: A Cloud Computing Testbed Cloud computing is gaining a foothold in the business world, but can clouds meet the specialized needs of scientists? That was one of the questions NERSC's Magellan cloud computing testbed explored between 2009 and 2011. The goal of Magellan, a project funded through the U.S. Department of Energy (DOE) Oce

  11. ARM - Measurement - Cloud base height

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    base height ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud base height For a given cloud or cloud layer, the lowest level of the atmosphere where cloud properties are detectable. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all

  12. ARM - Measurement - Cloud top height

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    top height ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud top height For a given cloud or cloud layer, the highest level of the atmosphere where cloud properties are detectable. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all

  13. Using doppler radar images to estimate aircraft navigational heading error

    DOE Patents [OSTI]

    Doerry, Armin W. (Albuquerque, NM); Jordan, Jay D. (Albuquerque, NM); Kim, Theodore J. (Albuquerque, NM)

    2012-07-03

    A yaw angle error of a motion measurement system carried on an aircraft for navigation is estimated from Doppler radar images captured using the aircraft. At least two radar pulses aimed at respectively different physical locations in a targeted area are transmitted from a radar antenna carried on the aircraft. At least two Doppler radar images that respectively correspond to the at least two transmitted radar pulses are produced. These images are used to produce an estimate of the yaw angle error.

  14. Federal Interagency Wind Turbine Radar Interference Mitigation Strategy |

    Office of Environmental Management (EM)

    Department of Energy Federal Interagency Wind Turbine Radar Interference Mitigation Strategy Federal Interagency Wind Turbine Radar Interference Mitigation Strategy Cover of the Federal Interagency Wind Turbine Radar Interference Mitigation Strategy report Wind development located within the line of sight of radar systems can cause clutter and interference, which at some radars has resulted in significant performance degradation. As wind turbines continue to be installed, and as advances in

  15. Wind speed response of marine non-precipitating stratocumulus clouds over a diurnal cycle in cloud-system resolving simulations

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kazil, J.; Feingold, G.; Yamaguchi, T.

    2015-10-21

    Observed and projected trends in large scale wind speed over the oceans prompt the question: how might marine stratocumulus clouds and their radiative properties respond to future changes in large scale wind speed? Wind speed drives the surface fluxes of sensible heat, moisture, and momentum, and thereby acts on cloud liquid water path (LWP) and cloud radiative properties. We present an investigation of the dynamical response of non-precipitating, overcast marine stratocumulus clouds to different wind speeds, all else equal. In cloud-system resolving simulations, we find that higher wind speed leads to faster boundary layer growth and stronger entrainment. The dynamicalmoredriver is enhanced buoyant production of turbulence kinetic energy (TKE) from latent heat release in cloud updrafts. LWP is enhanced during the night and in the morning at higher wind speed, and more strongly suppressed later in the day. Wind speed hence accentuates the diurnal LWP cycle by expanding the morning afternoon contrast. The higher LWP at higher wind speed does not, however, enhance cloud top cooling because in clouds with LWP ⪆ 50 g m?2, long wave emissions are very insensitive to LWP. This leads to the more general conclusion that in sufficiently thick stratocumulus clouds, additional boundary layer growth and entrainment due to a boundary layer moistening arises by stronger production of TKE from latent heat release in cloud updrafts, rather than from enhanced longwave cooling. We find furthermore that large scale wind modulates boundary layer decoupling. At nighttime and at low wind speed during daytime, it enhances decoupling in part by faster boundary layer growth and stronger entrainment, and in part because circulation driven by shear from large scale wind in the sub-cloud layer hinders vertical moisture transport between the surface and cloud base. With increasing wind speed, however, in decoupled daytime conditions, shear-driven circulation due to large scale wind takes over from buoyancy-driven circulation in transporting moisture from the surface to cloud base, and thereby reduces decoupling and helps maintain LWP. The cloud radiative effect (CRE) responds to changes in LWP and cloud fraction, and higher wind speed translates to a stronger diurnally averaged CRE. However, the sensitivity of the diurnally averaged CRE to wind speed decreases with increasing wind speed.less

  16. Ground penetrating radar surveys over an alluvial DNAPL site, Paducah Gaseous Diffusion Plant, Kentucky

    SciTech Connect (OSTI)

    Carpenter, P.J. |; Doll, W.E.; Phillips, B.E.

    1994-09-01

    Ground penetrating radar (GPR) surveys were used to map shallow sands and gravels which are DNAPL migration pathways at the Paducah Gaseous Diffusion Plant in western Kentucky. The sands and gravels occur as paleochannel deposits, at depths of 17-25 ft, embedded in Pleistocene lacustrine clays. More than 30 GPR profiles were completed over the Drop Test Area (DTA) to map the top and base of the paleochannel deposits, and to assess their lateral continuity. A bistatic radar system was used with antenna frequencies of 25 and 50 MHz. An average velocity of 0.25 ft/ns for silty and clayey materials above the paleochannel deposits was established from radar walkaway tests, profiles over culverts of known depth, and comparison of radar sections with borings. In the south portion of the DTA, strong reflections corresponded to the water table at approximately 9-10 ft, the top of the paleochannel deposits at approximately 18 ft, and to gravel horizons within these deposits. The base of these deposits was not visible on the radar sections. Depth estimates for the top of the paleochannel deposits (from 50 records) were accurate to within 2 ft across the southern portion of the DTA. Continuity of these sands and gravels could not be assessed due to interference from air-wave reflections and lateral changes in signal penetration depth. However, the sands and gravels appear to extend across the entire southern portion of the DTA, at depths as shallow as 17 ft. Ringing, air-wave reflections and diffractions from powerlines, vehicles, well casings, and metal equipment severly degraded GPR profiles in the northern portion of the DTA; depths computed from reflection times (where visible) were accurate to within 4 ft in this area. The paleochannel deposits are deeper to the north and northeast where DNAPL has apparently pooled (DNAPL was not directly imaged by the GPR, however). Existing hydrogeological models of the DTA will be revised.

  17. ARM - Evaluation Product - Precipitation Radar Moments Mapped...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    We would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Evaluation Product : Precipitation Radar Moments Mapped to a Cartesian Grid The Scanning...

  18. ARM Installs Aircraft Detection Radar System

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ARM Installs Aircraft Detection Radar System For improved safety in and around the ARM SGP CART site, the ARM Program recently purchased and installed an aircraft detection radar system at the central facility near Lamont, Oklahoma. The new system will enhance safety measures already in place at the central facility. The SGP CART site, especially the central facility, houses several instruments employing laser technology. These instruments are designed to be eye-safe and are not a hazard to

  19. Ionospheric acoustic and gravity waves associated with midlatitude thunderstorms

    SciTech Connect (OSTI)

    Lay, Erin H.; Shao, Xuan -Min; Kendrick, Alexander K.; Carrano, Charles S.

    2015-07-30

    Acoustic waves with periods of 24 min and gravity waves with periods of 616 min have been detected at ionospheric heights (25350 km) using GPS total electron content measurements. The area disturbed by these waves and the wave amplitudes have been associated with underlying thunderstorm activity. A statistical study comparing Next Generation Weather Radar thunderstorm measurements with ionospheric acoustic and gravity waves in the midlatitude U.S. Great Plains region was performed for the time period of MayJuly 2005. An increase of ionospheric acoustic wave disturbed area and amplitude is primarily associated with large thunderstorms (mesoscale convective systems). Ionospheric gravity wave disturbed area and amplitude scale with thunderstorm activity, with even small storms (i.e., individual storm cells) producing an increase of gravity waves.

  20. Wideband radar cross section reduction using two-dimensional phase gradient metasurfaces

    SciTech Connect (OSTI)

    Li, Yongfeng; Qu, Shaobo; Wang, Jiafu; Chen, Hongya; Zhang, Jieqiu; Xu, Zhuo; Zhang, Anxue

    2014-06-02

    Phase gradient metasurface (PGMs) are artificial surfaces that can provide pre-defined in-plane wave-vectors to manipulate the directions of refracted/reflected waves. In this Letter, we propose to achieve wideband radar cross section (RCS) reduction using two-dimensional (2D) PGMs. A 2D PGM was designed using a square combination of 49 split-ring sub-unit cells. The PGM can provide additional wave-vectors along the two in-plane directions simultaneously, leading to either surface wave conversion, deflected reflection, or diffuse reflection. Both the simulation and experiment results verified the wide-band, polarization-independent, high-efficiency RCS reduction induced by the 2D PGM.

  1. Stepped frequency ground penetrating radar

    DOE Patents [OSTI]

    Vadnais, Kenneth G.; Bashforth, Michael B.; Lewallen, Tricia S.; Nammath, Sharyn R.

    1994-01-01

    A stepped frequency ground penetrating radar system is described comprising an RF signal generating section capable of producing stepped frequency signals in spaced and equal increments of time and frequency over a preselected bandwidth which serves as a common RF signal source for both a transmit portion and a receive portion of the system. In the transmit portion of the system the signal is processed into in-phase and quadrature signals which are then amplified and then transmitted toward a target. The reflected signals from the target are then received by a receive antenna and mixed with a reference signal from the common RF signal source in a mixer whose output is then fed through a low pass filter. The DC output, after amplification and demodulation, is digitized and converted into a frequency domain signal by a Fast Fourier Transform. A plot of the frequency domain signals from all of the stepped frequencies broadcast toward and received from the target yields information concerning the range (distance) and cross section (size) of the target.

  2. IMPROVED CAPABILITIES FOR SITING WIND FARMS AND MITIGATING IMPACTS ON RADAR OBSERVATIONS

    SciTech Connect (OSTI)

    Chiswell, S.

    2010-01-15

    The development of efficient wind energy production involves challenges in technology and interoperability with other systems critical to the national mission. Wind turbines impact radar measurements as a result of their large reflectivity cross section as well as through the Doppler phase shift of their rotating blades. Wind farms can interfere with operational radar in multiple contexts, with degradation impacts on: weather detection such as tornado location, wind shear, and precipitation monitoring; tracking of airplanes where air traffic control software can lose the tracks of aircraft; and in identification of other low flying targets where a wind farm located close to a border might create a dead zone for detecting intruding objects. Objects in the path of an electromagnetic wave affect its propagation characteristics. This includes actual blockage of wave propagation by large individual objects and interference in wave continuity due to diffraction of the beam by individual or multiple objects. As an evolving industry, and the fastest growing segment of the energy sector, wind power is poised to make significant contributions in future energy generation requirements. The ability to develop comprehensive strategies for designing wind turbine locations that are mutually beneficial to both the wind industry that is dependent on production, and radar sites which the nation relies on, is critical to establishing reliable and secure wind energy. The mission needs of the Department of Homeland Security (DHS), Department of Defense (DOD), Federal Aviation Administration (FAA), and National Oceanographic and Atmospheric Administration (NOAA) dictate that the nation's radar systems remain uninhibited, to the maximum extent possible, by man-made obstructions; however, wind turbines can and do impact the surveillance footprint for monitoring airspace both for national defense as well as critical weather conditions which can impact life and property. As a result, a number of potential wind power locations have been contested on the basis of radar line of site. Radar line of site is dependent on local topography, and varies with atmospheric refractive index which is affected by weather and geographic conditions.

  3. The Mid-Latitude Continental Convective Clouds Experiment (MC3E)

    SciTech Connect (OSTI)

    Petersen,W.; Jensen,M.; Genio, A. D.; Giangrande, S.; Heymsfield, A.; Heymsfield, G.; Hou, A.; Kollias, P.; Orr, B.; Rutledge, S.; Schwaller, M.; Zipser, E.

    2010-03-15

    The Midlatitude Continental Convective Cloud Experiment (MC3E) will take place in central Oklahoma during the April-May 2011 period. The experiment is a collaborative effort between the U.S. Department of Energy Atmospheric Radition Measurement Program and the National Aeronautics and Space Administration's (NASA) Global Precipitation Measurement (GPM) mission Ground Validation program. The Intensive Observation Period leverages the unprecedented observing infrastructure currently available in the central United States, combined with an extensive sounding array, remote sensing and in situ aircraft observations, NASA GPM ground validation remote sensors and new ARM instrumentation purchased with American Recovery and Reinvestment Act funding. The overarching goal is to provide the most complete characterization of convective cloud systems, precipitation and the environment that has ever been obtained, providing constraints for model cumulus parameterizations and space-based rainfall observations over land that have never before been available. Several different components of convective processes tangible to the convective parameterization problem are targeted such as, pre-convective environment and convective initiation, updraft / downdraft dynamics, condensate transport and detrainment, precipitation and cloud microphysics, influence on the environment and radiation and a detailed description of the large-scale forcing. MC3E will use a new multi-scale observing strategy with the participation of a network of distributed sensors (both passive and active). The approach is to document in 3-D not only the full spectrum of precipitation rates, but also clouds, winds and moisture in an attempt to provide a holistic view of convective clouds and their feedback with the environment. A goal is to measure cloud and precipitation transitions and environmental quantities that are important for satellite retrieval algorithms, convective parameterization in large-scale models and cloud-resolving model simulations. This will be accomplished through the deployment of several different elements that complement the existing (and soon to become available) ARM facilities: a network of radiosonde stations, NASA scanning multi-frequency/parameter radar systems at three different frequencies (Ka/Ku/S), high-altitude remote sensing and in situ aircraft, wind profilers and a network of surface disdrometers. In addition to these special MC3E instruments, there will be important new instrumentation deployed by DOE at the ARM site including: 3 networked scanning X-band radar systems, a C-band scanning radar, a dual wavelength (Ka/W) scanning cloud radar, a Doppler lidar and upgraded vertically pointing millimeter cloud radar (MMCR) and micropulse lidar (MPL).To fully describe the properties of precipitating cloud systems, both in situ and remote sensing airborne observations are necessary. The NASA GPM-funded University of North Dakota (UND) Citation will provide in situ observations of precipitation-sized particles, ice freezing nuclei and aerosol concentrations. As a complement to the UND Citation's in situ observations, the NASA ER-2 will provide a high altitude satellite simulator platform that carrying a Ka/Ku band radar and passive microwave radiometers (10-183 GHZ).

  4. ET4169 Radar theory and systems

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Rainfall, clouds, wind, greenhouse gases Sea temperature, soil moisture, vegetation Ocean currents, polar ice, glaciers Questions: how much rain, ice, gas etc? 12 Titel van de ...

  5. Opaque cloud detection

    DOE Patents [OSTI]

    Roskovensky, John K. (Albuquerque, NM)

    2009-01-20

    A method of detecting clouds in a digital image comprising, for an area of the digital image, determining a reflectance value in at least three discrete electromagnetic spectrum bands, computing a first ratio of one reflectance value minus another reflectance value and the same two values added together, computing a second ratio of one reflectance value and another reflectance value, choosing one of the reflectance values, and concluding that an opaque cloud exists in the area if the results of each of the two computing steps and the choosing step fall within three corresponding predetermined ranges.

  6. Bringing Clouds into Focus

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Bringing Clouds into Focus Bringing Clouds into Focus A New Global Climate Model May Reduce the Uncertainty of Climate Forecasting May 11, 2010 Contact: John Hules, JAHules@lbl.gov , +1 510 486 6008 Randall-fig4.png The large data sets generated by the GCRM require new analysis and visualization capabilities. This 3D plot of vorticity isosurfaces was developed using VisIt, a 3D visualization tool with a parallel distributed architecture, which is being extended to support the geodesic grid used

  7. ARM - Cloud Twist

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Twist Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About ARM Global Warming FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans Cloud Twist Want to make your own version of Cloud Twist? Here are the files you will need. Floor Mat A low resolution image (7.3 MB) and high resolution image (53.2 MB) are available. Spinner Board A low resolution image (992.6 KB) and

  8. Cloud Based Applications and Platforms (Presentation)

    SciTech Connect (OSTI)

    Brodt-Giles, D.

    2014-05-15

    Presentation to the Cloud Computing East 2014 Conference, where we are highlighting our cloud computing strategy, describing the platforms on the cloud (including Smartgrid.gov), and defining our process for implementing cloud based applications.

  9. ARM - Measurement - Images of Clouds

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govMeasurementsImages of Clouds ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Images of Clouds Digital images of cloud scenes (various formats) from satellite, aircraft, and ground-based platforms. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a

  10. ARM - Measurement - Total cloud water

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    cloud water ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Total cloud water The total concentration (mass/vol) of ice and liquid water particles in a cloud; this includes condensed water content (CWC). Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a

  11. On the measurement of wind speeds in tornadoes with a portable CW/FM-CW Doppler radar

    SciTech Connect (OSTI)

    Bluestein, H.B. . School of Meteorology); Unruh, W.P. )

    1991-01-01

    Both the formation mechanism and structure of tornadoes are not yet well understood. The Doppler radar is probably the best remote-sensing instrument at present for determining the wind field in tornadoes. Although much has been learned about the non-supercell tornado from relatively close range using Doppler radars at fixed sites, close-range measurements in supercell tornadoes are relatively few. Doppler radar can increase significantly the number of high-resolution, sub-cloud base measurements of both the tornado vortex and its parent vortex in supercells, with simultaneous visual documentation. The design details and operation of the CW/FM-CW Doppler radar developed at the Los Alamos National Laboratory and used by storm-intercept teams at the Univ. of Oklahoma are described elsewhere. The radar transmits 1 W at 3 cm, and can be switched back and forth between CW and FM-CW modes. In the FM-CW mode the sweep repetition frequency is 15.575 kHz and the sweep width 1.9 MHz; the corresponding maximum unambiguous range and velocity, and range resolution are 5 km, {plus minus} 115 m s{sup {minus}1}, and 78 m respectively. The bistatic antennas, which have half-power beamwidths of 5{degree}, are easily pointed wit the aid of a boresighted VCR. FM-CW Data are recorded on the VCR, while voice documentation is recorded on the audio tape; video is recorded on another VCR. The radar and antennas are easily mounted on a tripod, and can be set up by three people in a minute or two. The purpose of this paper is to describe the signal processing techniques used to determine the Doppler spectrum in the FM-CW mode and a method of its interpretation in real time, and to present data gathered in a tornadic storm in 1990. 15 refs., 7 figs.

  12. Ionospheric acoustic and gravity waves associated with midlatitude thunderstorms

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lay, Erin H.; Shao, Xuan -Min; Kendrick, Alexander K.; Carrano, Charles S.

    2015-07-30

    Acoustic waves with periods of 2–4 min and gravity waves with periods of 6–16 min have been detected at ionospheric heights (25–350 km) using GPS total electron content measurements. The area disturbed by these waves and the wave amplitudes have been associated with underlying thunderstorm activity. A statistical study comparing Next Generation Weather Radar thunderstorm measurements with ionospheric acoustic and gravity waves in the midlatitude U.S. Great Plains region was performed for the time period of May–July 2005. An increase of ionospheric acoustic wave disturbed area and amplitude is primarily associated with large thunderstorms (mesoscale convective systems). Ionospheric gravity wavemore » disturbed area and amplitude scale with thunderstorm activity, with even small storms (i.e., individual storm cells) producing an increase of gravity waves.« less

  13. ARM - Cloud Word Seek

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Word Seek Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About ARM Global Warming FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans Cloud Word Seek

  14. Remote Sensing of Cirrus Particle Size Vertical Profile Using...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Category: Cloud Properties The time series of backscattering coefficients derived from lidar and Doppler millimeter-wave radar returns, as well as from balloon and aircraft...

  15. Discover the Benefits of Radar Imaging | Open Energy Information

    Open Energy Info (EERE)

    of Radar Imaging Jump to: navigation, search OpenEI Reference LibraryAdd to library Web Site: Discover the Benefits of Radar Imaging Author William V. Parker Published EIJ...

  16. Comments on: Texas Tech University mobile doppler radars provide...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    texas-tech-university-mobile-doppler-radars-provide-unique-wind-measurements-to-multi-instrument-doe-field-campaign...

  17. SGP Cloud and Land Surface Interaction Campaign (CLASIC): Science and Implementation Plan

    SciTech Connect (OSTI)

    MA Miller; R Avissar; LK Berg; SA Edgerton; ML Fischer; T Jackson; B.Kustas; PJ Lamb; GM McFarquhar; Q Min; B Schmid; MS Torn; DD Turner

    2007-06-30

    The Cloud and Land Surface Interaction Campaign is a field experiment designed to collect a comprehensive data set that can be used to quantify the interactions that occur between the atmosphere, biosphere, land surface, and subsurface. A particular focus will be on how these interactions modulate the abundance and characteristics of small and medium size cumuliform clouds that are generated by local convection. These interactions are not well understood and are responsible for large uncertainties in global climate models, which are used to forecast future climate states. The campaign will be conducted from June 8 to June 30, 2007, at the U.S. Department of Energys Atmospheric Radiation Measurement Climate Research Facility Southern Great Plains site. Data will be collected using eight aircraft equipped with a variety of specialized sensors, four specially instrumented surface sites, and two prototype surface radar systems. The architecture of Cloud and Land Surface Interaction Campaign includes a high-altitude surveillance aircraft and enhanced vertical thermodynamic and wind profile measurements that will characterize the synoptic scale structure of the clouds and the land surface within the Atmospheric Radiation Measurement Climate Research Facility Southern Great Plains site. Mesoscale and microscale structures will be sampled with a variety of aircraft, surface, and radar observations.

  18. Motion Measurement for Synthetic Aperture Radar.

    SciTech Connect (OSTI)

    Doerry, Armin W.

    2015-01-01

    Synthetic Aperture Radar (SAR) measures radar soundings from a set of locations typically along the flight path of a radar platform vehicle. Optimal focusing requires precise knowledge of the sounding source locations in 3 - D space with respect to the target scene. Even data driven focusing techniques (i.e. autofocus) requires some degree of initial fidelity in the measurements of the motion of the radar. These requirements may be quite stringent especially for fine resolution, long ranges, and low velocities. The principal instrument for measuring motion is typically an Inertial Measurement Unit (IMU), but these instruments have inherent limi ted precision and accuracy. The question is %22How good does an IMU need to be for a SAR across its performance space?%22 This report analytically relates IMU specifications to parametric requirements for SAR. - 4 - Acknowledgements Th e preparation of this report is the result of a n unfunded research and development activity . Although this report is an independent effort, it draws heavily from limited - release documentation generated under a CRADA with General Atomics - Aeronautical System, Inc. (GA - ASI), and under the Joint DoD/DOE Munitions Program Memorandum of Understanding. Sandia National Laboratories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of En ergy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000.

  19. TURBULENCE DECAY AND CLOUD CORE RELAXATION IN MOLECULAR CLOUDS

    SciTech Connect (OSTI)

    Gao, Yang; Law, Chung K.; Xu, Haitao

    2015-02-01

    The turbulent motion within molecular clouds is a key factor controlling star formation. Turbulence supports molecular cloud cores from evolving to gravitational collapse and hence sets a lower bound on the size of molecular cloud cores in which star formation can occur. On the other hand, without a continuous external energy source maintaining the turbulence, such as in molecular clouds, the turbulence decays with an energy dissipation time comparable to the dynamic timescale of clouds, which could change the size limits obtained from Jean's criterion by assuming constant turbulence intensities. Here we adopt scaling relations of physical variables in decaying turbulence to analyze its specific effects on the formation of stars. We find that the decay of turbulence provides an additional approach for Jeans' criterion to be achieved, after which gravitational infall governs the motion of the cloud core. This epoch of turbulence decay is defined as cloud core relaxation. The existence of cloud core relaxation provides a more complete understanding of the effect of the competition between turbulence and gravity on the dynamics of molecular cloud cores and star formation.

  20. Improved Arctic Cloud and Aerosol Research and Model Parameterizations

    SciTech Connect (OSTI)

    Kenneth Sassen

    2007-03-01

    In this report are summarized our contributions to the Atmospheric Measurement (ARM) program supported by the Department of Energy. Our involvement commenced in 1990 during the planning stages of the design of the ARM Cloud and Radiation Testbed (CART) sites. We have worked continuously (up to 2006) on our ARM research objectives, building on our earlier findings to advance our knowledge in several areas. Below we summarize our research over this period, with an emphasis on the most recent work. We have participated in several aircraft-supported deployments at the SGP and NSA sites. In addition to deploying the Polarization Diversity Lidar (PDL) system (Sassen 1994; Noel and Sassen 2005) designed and constructed under ARM funding, we have operated other sophisticated instruments W-band polarimetric Doppler radar, and midinfrared radiometer for intercalibration and student training purposes. We have worked closely with University of North Dakota scientists, twice co-directing the Citation operations through ground-to-air communications, and serving as the CART ground-based mission coordinator with NASA aircraft during the 1996 SUCCESS/IOP campaign. We have also taken a leading role in initiating case study research involving a number of ARM coinvestigators. Analyses of several case studies from these IOPs have been reported in journal articles, as we show in Table 1. The PDL has also participated in other major field projects, including FIRE II and CRYSTAL-FACE. In general, the published results of our IOP research can be divided into two categories: comprehensive cloud case study analyses to shed light on fundamental cloud processes using the unique CART IOP measurement capabilities, and the analysis of in situ data for the testing of remote sensing cloud retrieval algorithms. One of the goals of the case study approach is to provide sufficiently detailed descriptions of cloud systems from the data-rich CART environment to make them suitable for application to cloud modeling groups, such as the GEWEX Cloud Simulation Study (GCSS) Cirrus Working Groups. In this paper we summarize our IOP-related accomplishments.

  1. Clouds' Role in Sunlight Stopping

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Clouds' Role in Sunlight Stopping For original submission and image(s), see ARM Research Highlights http://www.arm.gov/science/highlights/ Research Highlight Clouds are energy traffic cops, controlling how much sunlight reaches Earth. Pacific Northwest National Laboratory (PNNL) researchers used long-term observations to show that the sunlight stopping power of each type of typical tropical cloud, and how frequently they occur, must be accurately simulated in climate models. Otherwise,

  2. ARM - Measurement - Cloud ice particle

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ice particle ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud ice particle Particles made of ice found in clouds. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or

  3. ARM - Measurement - Cloud optical depth

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    optical depth ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud optical depth Amount of light cloud droplets or ice particles prevent from passing through a column of atmosphere. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all

  4. TWP Island Cloud Trail Studies

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    a key to understanding boundary layer cloud formation in the tropics. Except during El Nio periods, Nauru represents a divergent region of the ocean upwind from the...

  5. ARM - Measurement - Cloud condensation nuclei

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AOS : Aerosol Observing System CCN : Cloud Condensation Nuclei Particle Counter TDMA : Tandem Differential Mobility Analyzer Field Campaign Instruments AMT : Aerosol Modeling...

  6. Novel Use of P- and S-Wave Seismic Attenuation for Deep Natural...

    Office of Scientific and Technical Information (OSTI)

    Title: Novel Use of P- and S-Wave Seismic Attenuation for Deep Natural Gas Exploration and ... Sponsoring Org: USDOE Country of Publication: United States Language: English Word Cloud ...

  7. Indirect and Semi-Direct Aerosol Campaign: The Impact of Arctic Aerosols on Clouds

    SciTech Connect (OSTI)

    McFarquhar, Greg; Ghan, Steven J.; Verlinde, J.; Korolev, Alexei; Strapp, J. Walter; Schmid, Beat; Tomlinson, Jason M.; Wolde, Mengistu; Brooks, Sarah D.; Cziczo, Daniel J.; Dubey, Manvendra K.; Fan, Jiwen; Flynn, Connor J.; Gultepe, Ismail; Hubbe, John M.; Gilles, Mary K.; Laskin, Alexander; Lawson, Paul; Leaitch, W. R.; Liu, Peter S.; Liu, Xiaohong; Lubin, Dan; Mazzoleni, Claudio; Macdonald, A. M.; Moffet, Ryan C.; Morrison, H.; Ovchinnikov, Mikhail; Shupe, Matthew D.; Turner, David D.; Xie, Shaocheng; Zelenyuk, Alla; Bae, Kenny; Freer, Matthew; Glen, Andrew

    2011-02-01

    A comprehensive dataset of microphysical and radiative properties of aerosols and clouds in the arctic boundary layer in the vicinity of Barrow, Alaska was collected in April 2008 during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) sponsored by the Department of Energy Atmospheric Radiation Measurement (ARM) and Atmospheric Science Programs. The primary aim of ISDAC was to examine indirect effects of aerosols on clouds that contain both liquid and ice water. The experiment utilized the ARM permanent observational facilities at the North Slope of Alaska (NSA) in Barrow. These include a cloud radar, a polarized micropulse lidar, and an atmospheric emitted radiance interferometer as well as instruments specially deployed for ISDAC measuring aerosol, ice fog, precipitation and spectral shortwave radiation. The National Research Council of Canada Convair-580 flew 27 sorties during ISDAC, collecting data using an unprecedented 42 cloud and aerosol instruments for more than 100 hours on 12 different days. Data were obtained above, below and within single-layer stratus on 8 April and 26 April 2008. These data enable a process-oriented understanding of how aerosols affect the microphysical and radiative properties of arctic clouds influenced by different surface conditions. Observations acquired on a heavily polluted day, 19 April 2008, are enhancing this understanding. Data acquired in cirrus on transit flights between Fairbanks and Barrow are improving our understanding of the performance of cloud probes in ice. Ultimately the ISDAC data will be used to improve the representation of cloud and aerosol processes in models covering a variety of spatial and temporal scales, and to determine the extent to which long-term surface-based measurements can provide retrievals of aerosols, clouds, precipitation and radiative heating in the Arctic.

  8. Widget:LogoCloud | Open Energy Information

    Open Energy Info (EERE)

    LogoCloud Jump to: navigation, search This widget adds css selectors and javascript for the Template:LogoCloud. For example: Widget:LogoCloud Retrieved from "http:...

  9. Development of a Drillrod/Telemetry Radar

    SciTech Connect (OSTI)

    Raton Technology Research, Inc.

    1999-11-12

    Efficient extraction of deeply buried natural resources is dependent upon accurate geologic models. The model becomes the basis for developing plans for extraction of the resource. Geoscientists working in geothermal and hydrocarbon recovery have a great deal in common with fellow geoscientists working in the mining industry. They appreciate the intractable problem of increasing the depth of investigation to tens of meters from the wellbore. The goal of this project was to develop a borehole radar tool to acquire data within tens of meters from the wellbore. For geothermal and hydrocarbon applications, the tool was to acquire data for mapping fractures surrounding the wellbore. In mining of coal, the radar acquires data for determining coal seam thickness and detecting geologic anomalies ahead of mining.

  10. Final Report – Study of Shortwave Spectra in Fully 3D Environment. Synergy Between Scanning Radars and Spectral Radiation Measurements

    SciTech Connect (OSTI)

    Chiu, Jui-Yuan

    2015-09-14

    ARM set out 20 years ago to “close” the radiation problem, that is, to improve radiation models to the point where they could routinely predict the observed spectral radiation fluxes knowing the optical properties of the surface and of gases, clouds and aerosols in the atmosphere. Only then could such radiation models form a proper springboard for global climate model (GCM) parameterizations of spectral radiation. Sustained efforts have more or less achieved that goal with regard to longwave radiation; ASR models now routinely predict ARM spectral longwave radiances to 1–2%. Similar efforts in the shortwave have achieved far less; the successes are mainly for carefully selected 1D stratiform cloud cases. Such cases amount, even with the most optimistic interpretation, to no more than 30% of all cases at SGP. The problem has not been lack of effort but lack of appropriate instruments.The new ARM stimulus-funded instruments, with their new capabilities, will dramatically improve this situation and once again make progress possible on the shortwave problem. The new shortwave spectrometers will provide a reliable, calibrated record including the near infrared – and for other climatic regimes than SGP. The new scanning radars will provide the 3D cloud view, making it possible to tackle fully 3D situations. Thus, our main theme for the project is the understanding and closure of the surface spectral shortwave radiation problem in fully 3D cloud situations by combining the new ARM scanning radars and shortwave spectrometers with the arsenal of radiative transfer tools.

  11. Zenith Radiance Retrieval of Cloud Properties

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    retrievals of cloud properties from the AMF/COPS campaign Preliminary retrievals of cloud properties from the AMF/COPS campaign Christine Chiu, UMBC/JCET Alexander Marshak, GSFC Yuri Knyazikhin, Boston University Warren Wiscombe, GSFC Christine Chiu, UMBC/JCET Alexander Marshak, GSFC Yuri Knyazikhin, Boston University Warren Wiscombe, GSFC The cloud optical properties of interest are: The cloud optical properties of interest are: * Cloud optical depth τ - the great unknown * Radiative cloud

  12. Testing a New Cirrus Cloud Parameterizaton

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Institute of Oceanography La Jolla, California Introduction Cirrus cloud cover and ice water content (IWC) are the two most important properties of cirrus clouds. However, in...

  13. Dynamics of Molecular Clouds: Observations, Simulations, and...

    Office of Scientific and Technical Information (OSTI)

    Conference: Dynamics of Molecular Clouds: Observations, Simulations, and NIF Experiments Citation Details In-Document Search Title: Dynamics of Molecular Clouds: Observations,...

  14. Clouds Environmental Ltd | Open Energy Information

    Open Energy Info (EERE)

    Clouds Environmental Ltd Jump to: navigation, search Name: Clouds Environmental Ltd Place: Portsmouth, United Kingdom Zip: PO3 5EG Product: Independent consultancy specialising in...

  15. Cloud Properties Working Group Break Out Session

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    relation to fall speeds, implications for previous measurements. (Mitchell) Q8: Geoengineering of cirrus clouds (Mitchell) Q9: Cold cloud phase partitioning: Roles of...

  16. ARM - Evaluation Product - Corrected Precipitation Radar Moments in Antenna

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Coordinates ProductsCorrected Precipitation Radar Moments in Antenna Coordinates Documentation Use the Data File Inventory tool to view data availability at the file level. Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Evaluation Product : Corrected Precipitation Radar Moments in Antenna Coordinates Raw moments from the scanning ARM precipitation radars (SAPRs) are subject to a number of instrumental and atmospheric phenomena that must be

  17. Improving Radar Antenna Performance with Eigenvalue Processing of

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cross-Polarization Signals - Energy Innovation Portal Improving Radar Antenna Performance with Eigenvalue Processing of Cross-Polarization Signals Brookhaven National Laboratory Contact BNL About This Technology Technology Marketing Summary This invention comprises an atmospheric radar apparatus and a method for measuring a meteorological or other type of variable of a target having reflection symmetry without bias caused by coherent antenna cross-polar coupling in the atmospheric radar

  18. 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A beautiful day There are lots of great clouds in the sky, and PI Prairie Dog needs to get to his instrument, the Millimeter Wave Cloud Radar (MMCR), to take some important...

  19. Inversion of synthetic aperture radar interferograms for sources...

    Open Energy Info (EERE)

    Inversion of synthetic aperture radar interferograms for sources of production-related subsidence at the Dixie Valley geothermal field Jump to: navigation, search OpenEI Reference...

  20. Title: Radar-observed convective characteristics during TWP-ICE

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    will describe the convective systems observed during the project by two scanning C-band Doppler radars, one of which will provide dual-polarization measurements, and ARM's...

  1. Wind Turbine Radar Interference Mitigation Working Group Releases New Report

    Broader source: Energy.gov [DOE]

    While wind energy presents many benefits, spinning wind turbines can interfere with weather, air traffic control, and air surveillance radar systems. As advances in wind technology enable turbines...

  2. Modeling Of Surface Deformation From Satellite Radar Interferometry...

    Open Energy Info (EERE)

    Salton Sea geothermal field is modeled using results from satellite radar interferometry, data from leveling surveys, and observations from the regional GPS network. The field is...

  3. Radiative Heating of the ISCCP Upper Level Cloud Regimes and its Impact on the Large-scale Tropical Circulation

    SciTech Connect (OSTI)

    Li, Wei; Schumacher, Courtney; McFarlane, Sally A.

    2013-01-31

    Radiative heating profiles of the International Satellite Cloud Climatology Project (ISCCP) cloud regimes (or weather states) were estimated by matching ISCCP observations with radiative properties derived from cloud radar and lidar measurements from the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) sites at Manus, Papua New Guinea, and Darwin, Australia. Focus was placed on the ISCCP cloud regimes containing the majority of upper level clouds in the tropics, i.e., mesoscale convective systems (MCSs), deep cumulonimbus with cirrus, mixed shallow and deep convection, and thin cirrus. At upper levels, these regimes have average maximum cloud occurrences ranging from 30% to 55% near 12 km with variations depending on the location and cloud regime. The resulting radiative heating profiles have maxima of approximately 1 K/day near 12 km, with equal heating contributions from the longwave and shortwave components. Upper level minima occur near 15 km, with the MCS regime showing the strongest cooling of 0.2 K/day and the thin cirrus showing no cooling. The gradient of upper level heating ranges from 0.2 to 0.4 K/(day?km), with the most convectively active regimes (i.e., MCSs and deep cumulonimbus with cirrus) having the largest gradient. When the above heating profiles were applied to the 25-year ISCCP data set, the tropics-wide average profile has a radiative heating maximum of 0.45Kday-1 near 250 hPa. Column-integrated radiative heating of upper level cloud accounts for about 20% of the latent heating estimated by the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR). The ISCCP radiative heating of tropical upper level cloud only slightly modifies the response of an idealized primitive equation model forced with the tropics-wide TRMM PR latent heating, which suggests that the impact of upper level cloud is more important to large-scale tropical circulation variations because of convective feedbacks rather than direct forcing by the cloud radiative heating profiles. However, the height of the radiative heating maxima and gradient of the heating profiles are important to determine the sign and patterns of the horizontal circulation anomaly driven by radiative heating at upper levels.

  4. Evaluation of high‐level clouds in cloud resolving model...

    Office of Scientific and Technical Information (OSTI)

    ... Res., 104, 24,527-24,545. Rasmussen, R. M., I. Geresdi, G. Thompson, K. Manning, and E. Karplus (2002), Freezing drizzle formation in stably stratified layer clouds: The role of ...

  5. ARM - Field Campaign - Cloud IOP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govCampaignsCloud IOP ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Cloud IOP 1998.04.27 - 1998.05.17 Lead Scientist : Gerald Mace For data sets, see below. Summary Monday, April 27, 1998 IOP Opening Activities: Heavy rain (nearly 2.5" since 12Z 4/26/98) at the central facility (CF) dominated the first day of the Cloud Physics/Single Column Model IOP and limited the daily activities. A 1430 GMT

  6. cloud | OpenEI Community

    Open Energy Info (EERE)

    - 13:42 How cleantech-as-a-service will drive renewable energy adoption 2015 adoption Big Data clean tech clean-tech cleantech cleantech forum cleantech-as-a-service cloud...

  7. Radar-cross-section reduction of wind turbines. part 1.

    SciTech Connect (OSTI)

    Brock, Billy C.; Loui, Hung; McDonald, Jacob J.; Paquette, Joshua A.; Calkins, David A.; Miller, William K.; Allen, Steven E.; Clem, Paul Gilbert; Patitz, Ward E.

    2012-03-05

    In recent years, increasing deployment of large wind-turbine farms has become an issue of growing concern for the radar community. The large radar cross section (RCS) presented by wind turbines interferes with radar operation, and the Doppler shift caused by blade rotation causes problems identifying and tracking moving targets. Each new wind-turbine farm installation must be carefully evaluated for potential disruption of radar operation for air defense, air traffic control, weather sensing, and other applications. Several approaches currently exist to minimize conflict between wind-turbine farms and radar installations, including procedural adjustments, radar upgrades, and proper choice of low-impact wind-farm sites, but each has problems with limited effectiveness or prohibitive cost. An alternative approach, heretofore not technically feasible, is to reduce the RCS of wind turbines to the extent that they can be installed near existing radar installations. This report summarizes efforts to reduce wind-turbine RCS, with a particular emphasis on the blades. The report begins with a survey of the wind-turbine RCS-reduction literature to establish a baseline for comparison. The following topics are then addressed: electromagnetic model development and validation, novel material development, integration into wind-turbine fabrication processes, integrated-absorber design, and wind-turbine RCS modeling. Related topics of interest, including alternative mitigation techniques (procedural, at-the-radar, etc.), an introduction to RCS and electromagnetic scattering, and RCS-reduction modeling techniques, can be found in a previous report.

  8. Mechanisms of Convective Cloud Organization by Cold Pools over Tropical Warm Ocean during the AMIE/DYNAMO Field Campaign

    SciTech Connect (OSTI)

    Feng, Zhe; Hagos, Samson M.; Rowe, Angela; Burleyson, Casey D.; Martini, Matus; de Szoeke, S.

    2015-06-01

    This paper investigates the mechanisms of convective cloud organization by precipitation-driven cold pools over the warm tropical Indian Ocean during the 2011 Atmospheric Radiation Measurement (ARM) Madden-Julian Oscillation (MJO) Investigation Experiment / Dynamics of the MJO (AMIE/DYNAMO) field campaign. A high-resolution regional model simulation is performed using the Weather Research and Forecasting model during the transition from suppressed to active phases of the November 2011 MJO. The simulated cold pool lifetimes, spatial extent and thermodynamic properties agree well with the radar and ship-borne observations from the field campaign. The thermodynamic and dynamic structures of the outflow boundaries of isolated and intersecting cold pools in the simulation and the associated secondary cloud populations are examined. Intersecting cold pools last more than twice as long, are twice as large, 41% more intense (measured by buoyancy), and 62% deeper than isolated cold pools. Consequently, intersecting cold pools trigger 73% more convective clouds than isolated ones. This is possibly due to stronger outflows that enhance secondary updraft velocities by up to 45%. However, cold pool-triggered convective clouds grow into deep convection not because of the stronger secondary updrafts at cloud base, but rather due to closer spacing (aggregation) between clouds and larger cloud clusters that formed along the cold pool boundaries when they intersect. The close spacing of large clouds moistens the local environment and reduces entrainment drying, allowing the clouds to further develop into deep convection. Implications to the design of future convective parameterization with cold pool-modulated entrainment rates are discussed.

  9. ANALYTICAL SOLUTION FOR WAVES IN PLANETS WITH ATMOSPHERIC SUPERROTATION. I. ACOUSTIC AND INERTIA-GRAVITY WAVES

    SciTech Connect (OSTI)

    Peralta, J.; Lpez-Valverde, M. A.; Imamura, T.; Read, P. L.; Luz, D.; Piccialli, A.

    2014-07-01

    This paper is the first of a two-part study devoted to developing tools for a systematic classification of the wide variety of atmospheric waves expected on slowly rotating planets with atmospheric superrotation. Starting with the primitive equations for a cyclostrophic regime, we have deduced the analytical solution for the possible waves, simultaneously including the effect of the metric terms for the centrifugal force and the meridional shear of the background wind. In those cases when the conditions for the method of the multiple scales in height are met, these wave solutions are also valid when vertical shear of the background wind is present. A total of six types of waves have been found and their properties were characterized in terms of the corresponding dispersion relations and wave structures. In this first part, only waves that are direct solutions of the generic dispersion relation are studiedacoustic and inertia-gravity waves. Concerning inertia-gravity waves, we found that in the cases of short horizontal wavelengths, null background wind, or propagation in the equatorial region, only pure gravity waves are possible, while for the limit of large horizontal wavelengths and/or null static stability, the waves are inertial. The correspondence between classical atmospheric approximations and wave filtering has been examined too, and we carried out a classification of the mesoscale waves found in the clouds of Venus at different vertical levels of its atmosphere. Finally, the classification of waves in exoplanets is discussed and we provide a list of possible candidates with cyclostrophic regimes.

  10. The Mid-latitude Continental Convective Clouds (MC3E) Experiment Final Campaign Report

    SciTech Connect (OSTI)

    Jensen, M; Giangrande, S; Kollias, P

    2014-04-01

    The Mid-latitude Continental Convective Clouds Experiment (MC3E) took place from April 22 through June 6, 2011, centered at the ARM Southern Great Plains site (http://www.arm.gov/sites/sgp) in northcentral Oklahoma. MC3E was a collaborative effort between the ARM Climate Research Facility and the National Aeronautics and Space Administrations (NASAs) Global Precipitation Measurement (GPM) mission Ground Validation (GV) program. The campaign leveraged the largest ground-based observing infrastructure available in the central United States, including recent upgrades through the American Recovery and Reinvestment Act of 2009, combined with an extensive sounding array, remote sensing and in situ aircraft observations, and additional radar and in situ precipitation instrumentation. The overarching goal of the campaign was to provide a three-dimensional characterization of convective clouds and precipitation for the purpose of improving the representation of convective lifecycle in atmospheric models and the reliability of satellite-based retrievals of precipitation.

  11. The Mid-latitude Continental Convective Clouds (MC3E) Experiment Final Campaign Report

    SciTech Connect (OSTI)

    Jensen, Michael; Kollias, Pavlos; Giangrande, Scott

    2014-04-01

    The Mid-latitude Continental Convective Clouds Experiment (MC3E) took place from April 22 through June 6, 2011, centered at the ARM Southern Great Plains site (http://www.arm.gov/sites/sgp) in northcentral Oklahoma. MC3E was a collaborative effort between the ARM Climate Research Facility and the National Aeronautics and Space Administration’s (NASA’s) Global Precipitation Measurement (GPM) mission Ground Validation (GV) program. The campaign leveraged the largest ground-based observing infrastructure available in the central United States, including recent upgrades through the American Recovery and Reinvestment Act of 2009, combined with an extensive sounding array, remote sensing and in situ aircraft observations, and additional radar and in situ precipitation instrumentation. The overarching goal of the campaign was to provide a three-dimensional characterization of convective clouds and precipitation for the purpose of improving the representation of convective lifecycle in atmospheric models and the reliability of satellite-based retrievals of precipitation.

  12. Final Technical Report for "Radiative Heating Associated with Tropical Convective Cloud Systems: Its Importance at Meso and Global Scales"

    SciTech Connect (OSTI)

    Schumacher, Courtney

    2012-12-13

    Heating associated with tropical cloud systems drive the global circulation. The overall research objectives of this project were to i) further quantify and understand the importance of heating in tropical convective cloud systems with innovative observational techniques, and ii) use global models to determine the large-scale circulation response to variability in tropical heating profiles, including anvil and cirrus cloud radiative forcing. The innovative observational techniques used a diversity of radar systems to create a climatology of vertical velocities associated with the full tropical convective cloud spectrum along with a dissection of the of the total heating profile of tropical cloud systems into separate components (i.e., the latent, radiative, and eddy sensible heating). These properties were used to validate storm-scale and global climate models (GCMs) and were further used to force two different types of GCMs (one with and one without interactive physics). While radiative heating was shown to account for about 20% of the total heating and did not have a strong direct response on the global circulation, the indirect response was important via its impact on convection, esp. in how radiative heating impacts the tilt of heating associated with the Madden-Julian Oscillation (MJO), a phenomenon that accounts for most tropical intraseasonal variability. This work shows strong promise in determining the sensitivity of climate models and climate processes to heating variations associated with cloud systems.

  13. Radar transponder apparatus and signal processing technique

    DOE Patents [OSTI]

    Axline, Jr., Robert M. (Albuquerque, NM); Sloan, George R. (Albuquerque, NM); Spalding, Richard E. (Albuquerque, NM)

    1996-01-01

    An active, phase-coded, time-grating transponder and a synthetic-aperture radar (SAR) and signal processor means, in combination, allow the recognition and location of the transponder (tag) in the SAR image and allow communication of information messages from the transponder to the SAR. The SAR is an illuminating radar having special processing modifications in an image-formation processor to receive an echo from a remote transponder, after the transponder receives and retransmits the SAR illuminations, and to enhance the transponder's echo relative to surrounding ground clutter by recognizing special transponder modulations from phase-shifted from the transponder retransmissions. The remote radio-frequency tag also transmits information to the SAR through a single antenna that also serves to receive the SAR illuminations. Unique tag-modulation and SAR signal processing techniques, in combination, allow the detection and precise geographical location of the tag through the reduction of interfering signals from ground clutter, and allow communication of environmental and status information from said tag to be communicated to said SAR.

  14. Radar transponder apparatus and signal processing technique

    DOE Patents [OSTI]

    Axline, R.M. Jr.; Sloan, G.R.; Spalding, R.E.

    1996-01-23

    An active, phase-coded, time-grating transponder and a synthetic-aperture radar (SAR) and signal processor means, in combination, allow the recognition and location of the transponder (tag) in the SAR image and allow communication of information messages from the transponder to the SAR. The SAR is an illuminating radar having special processing modifications in an image-formation processor to receive an echo from a remote transponder, after the transponder receives and retransmits the SAR illuminations, and to enhance the transponder`s echo relative to surrounding ground clutter by recognizing special transponder modulations from phase-shifted from the transponder retransmissions. The remote radio-frequency tag also transmits information to the SAR through a single antenna that also serves to receive the SAR illuminations. Unique tag-modulation and SAR signal processing techniques, in combination, allow the detection and precise geographical location of the tag through the reduction of interfering signals from ground clutter, and allow communication of environmental and status information from said tag to be communicated to said SAR. 4 figs.

  15. Impulse radar with swept range gate

    DOE Patents [OSTI]

    McEwan, T.E.

    1998-09-08

    A radar range finder and hidden object locator is based on ultra-wide band radar with a high resolution swept range gate. The device generates an equivalent time amplitude scan with a typical range of 4 inches to 20 feet, and an analog range resolution as limited by a jitter of on the order of 0.01 inches. A differential sampling receiver is employed to effectively eliminate ringing and other aberrations induced in the receiver by the near proximity of the transmit antenna, so a background subtraction is not needed, simplifying the circuitry while improving performance. Techniques are used to reduce clutter in the receive signal, such as decoupling the receive and transmit cavities by placing a space between them, using conductive or radiative damping elements on the cavities, and using terminating plates on the sides of the openings. The antennas can be arranged in a side-by-side parallel spaced apart configuration or in a coplanar opposed configuration which significantly reduces main bang coupling. 25 figs.

  16. Impulse radar with swept range gate

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1998-09-08

    A radar range finder and hidden object locator is based on ultra-wide band radar with a high resolution swept range gate. The device generates an equivalent time amplitude scan with a typical range of 4 inches to 20 feet, and an analog range resolution as limited by a jitter of on the order of 0.01 inches. A differential sampling receiver is employed to effectively eliminate ringing and other aberrations induced in the receiver by the near proximity of the transmit antenna (10), so a background subtraction is not needed, simplifying the circuitry while improving performance. Techniques are used to reduce clutter in the receive signal, such as decoupling the receive (24) and transmit cavities (22) by placing a space between them, using conductive or radiative damping elements on the cavities, and using terminating plates on the sides of the openings. The antennas can be arranged in a side-by-side parallel spaced apart configuration or in a coplanar opposed configuration which significantly reduces main bang coupling.

  17. Evaluation of high-level clouds in cloud resolving model simulations...

    Office of Scientific and Technical Information (OSTI)

    Evaluation of high-level clouds in cloud resolving model simulations with ARM and KWAJEX observations: HIGH CLOUD IN CRM Citation Details In-Document Search This content will ...

  18. Dispersion of Cloud Droplet Size Distributions, Cloud Parameterizations and Indirect Aerosol Effects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Dispersion of Cloud Droplet Size Distributions, Cloud Parameterizations, and Indirect Aerosol Effects P. H. Daum and Y. Liu Brookhaven National Laboratory Upton, New York Introduction Most studies of the effect of aerosols on cloud radiative properties have considered only changes in the cloud droplet concentration, neglecting changes in the spectral shape of the cloud droplet size distribution. However, it has been shown that that the spectral dispersion of the cloud droplet size distribution

  19. Intercomparison of model simulations of mixed-phase clouds observed...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. I: Single layer cloud Citation Details ...

  20. Signal Processing System for the CASA Integrated Project I Radars

    SciTech Connect (OSTI)

    Bharadwaj, Nitin; Chandrasekar, V.; Junyent, Francesc

    2010-09-01

    This paper describes the waveform design space and signal processing system for dual-polarization Doppler weather radar operating at X band. The performance of the waveforms is presented with ground clutter suppression capability and mitigation of range velocity ambiguity. The operational waveform is designed based on operational requirements and system/hardware requirements. A dual Pulse Repetition Frequency (PRF) waveform was developed and implemented for the first generation X-band radars deployed by the Center for Collaborative Adaptive Sensing of the Atmosphere (CASA). This paper presents an evaluation of the performance of the waveforms based on simulations and data collected by the first-generation CASA radars during operations.

  1. ARM - Field Campaign - 2001 Multi-Frequency Radar IOP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govCampaigns2001 Multi-Frequency Radar IOP ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : 2001 Multi-Frequency Radar IOP 2001.03.01 - 2001.09.30 Lead Scientist : Stephen Sekelsky Data Availability http://abyss.ecs.umass.edu For data sets, see below. Summary Install UMass and NOAA Aeronomy Laboratory "guest instrument" radars at the SGP CART site adjacent to the MMCR system. Both the UMass and

  2. Mitigating Wind-Radar Interference | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Mitigating Wind-Radar Interference Mitigating Wind-Radar Interference April 1, 2013 - 12:54pm Addthis This is an excerpt from the First Quarter 2013 edition of the Wind Program R&D Newsletter. The U.S. Department of Energy (DOE) and federal agency partners recently completed the final operational field test in a 2-year initiative to accelerate the deployment of the most promising new technologies for mitigating radar interference caused by the physical and electromagnetic effects of wind

  3. ARM - Facility News Article

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    New Data Stream Available from Millimeter Wave Cloud Radar Bookmark and Share Inside the instrument shelter, the MMCR data system collects radar spectral data and processes these into reflectivity, vertical velocities, and spectral width. As a result of upgrades to the Millimeter Wave Cloud Radar (MMCR) processors (see http://www.arm.gov/acrf/updates051504.stm#nsammcr) at the ARM Climate Research Facility Southern Great Plains (SGP) and North Slope of Alaska (NSA) locales, two MMCR data

  4. Time-frequency analysis of synthetic aperture radar signals

    SciTech Connect (OSTI)

    Johnston, B.

    1996-08-01

    Synthetic aperture radar (SAR) has become an important tool for remote sensing of the environment. SAR is a set of digital signal processing algorithms that are used to focus the signal returned to the radar because radar systems in themselves cannot produce the high resolution images required in remote sensing applications. To reconstruct an image, several parameters must be estimated and the quality of output image depends on the degree of accuracy of these parameters. In this thesis, we derive the fundamental SAR algorithms and concentrate on the estimation of one of its critical parameters. We show that the common technique for estimating this particular parameter can sometimes lead to erroneous results and reduced quality images. We also employ time-frequency analysis techniques to examine variations in the radar signals caused by platform motion and show how these results can be used to improve output image quality.

  5. What Makes Clouds Form, Grow and Die?

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Makes Clouds Form, Grow and Die? What Makes Clouds Form, Grow and Die? Simulations Show Raindrops Physics May Affect Climate Model Accuracy February 19, 2015 thunderstorm Brazil shuttle NASA 1984 540 PNNL scientists used real-world observations to simulate how small clouds are likely to stay shallow, while larger clouds grow deeper because they mix with less dry air. Pictured are small and large thunderstorms growing over southern Brazil, taken from the space shuttle. Image: NASA Johnson Space

  6. Radiative Effects of Cloud Inhomogeneity and

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Radiative Effects of Cloud Inhomogeneity and Geometric Association Over the Tropical Western Pacific Warm Pool X. Wu National Center for Atmospheric Research (a) Boulder, Colorado X. -Z. Liang Illinois State Water Survey Champaign, Illinois Introduction The representation of cloud systems and cloud-radiation interaction is considered to be one of major uncertainties in general circulation models (GCMs). This arises because (1) complete observations of cloud systems are impossible and available

  7. Layered Atlantic Smoke Interactions with Clouds

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Layered Atlantic Smoke Interactions with Clouds Island in the South Atlantic Ocean. Warm African winds combine with the cool sea surface temperatures and form a large stratocumulus deck, transitioning to year-round trade-wind shallow cumulus at the location of Ascension Island. These clouds and myriad aerosol-cloud-radiation interactions will be studied. Using a portable observatory, or ARM Mobile Facility (AMF), that contains some of most advanced atmospheric research instrumentation for cloud,

  8. INTERAGENCY FIELD TEST & EVALUATION OF WIND TURBINE - RADAR INTERFERENCE

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    MITIGATION TECHNOLOGIES | Department of Energy INTERAGENCY FIELD TEST & EVALUATION OF WIND TURBINE - RADAR INTERFERENCE MITIGATION TECHNOLOGIES INTERAGENCY FIELD TEST & EVALUATION OF WIND TURBINE - RADAR INTERFERENCE MITIGATION TECHNOLOGIES The documents below include 1) a report that summarizes the Interagency Field Test & Evaluation (IFT&E) program and publicly available results from the tests and 2) summaries of three field tests designed to measure the impact of wind

  9. ARM - Field Campaign - Measurement of Aerosols, Radiation and CloUds over

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the Southern Oceans (MARCUS) govCampaignsMeasurement of Aerosols, Radiation and CloUds over the Southern Oceans (MARCUS) Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Measurement of Aerosols, Radiation and CloUds over the Southern Oceans (MARCUS) 2017.09.01 - 2018.04.01 Lead Scientist : Greg McFarquhar Abstract The Southern Ocean (SO) is the stormiest place on Earth, buffeted by winds and waves that circle the ice of Antarctica,

  10. ARM Data for Cloud Parameterization

    SciTech Connect (OSTI)

    Xu, Kuan-Man

    2006-10-02

    The PI's ARM investigation (DE-IA02-02ER633 18) developed a physically-based subgrid-scale saturation representation that fully considers the direct interactions of the parameterized subgrid-scale motions with subgrid-scale cloud microphysical and radiative processes. Major accomplishments under the support of that interagency agreement are summarized in this paper.

  11. Unlocking the Secrets of Clouds

    Office of Energy Efficiency and Renewable Energy (EERE)

    Clouds may look soft, fluffy and harmless to the untrained eye, but to an expert climate model scientist they represent great challenges. Fortunately the Atmospheric Radiation Measurement (ARM) Climate and Research Facility is kicking off a five-month study which should significantly clear the air.

  12. Lidar Investigation of Tropical Nocturnal Boundary Layer Aerosols and Cloud Macrophysics

    SciTech Connect (OSTI)

    Manoj, M. G.; Devara, PC S.; Taraphdar, Sourav

    2013-10-01

    Observational evidence of two-way association between nocturnal boundary layer aerosols and cloud macrophysical properties under different meteorological conditions is reported in this paper. The study has been conducted during 2008-09 employing a high space-time resolution polarimetric micro-pulse lidar over a tropical urban station in India. Firstly, the study highlights the crucial role of boundary layer aerosols and background meteorology on the formation and structure of low-level stratiform clouds in the backdrop of different atmospheric stability conditions. Turbulent mixing induced by the wind shear at the station, which is associated with a complex terrain, is found to play a pivotal role in the formation and structural evolution of nocturnal boundary layer clouds. Secondly, it is shown that the trapping of energy in the form of outgoing terrestrial radiation by the overlying low-level clouds can enhance the aerosol mixing height associated with the nocturnal boundary layer. To substantiate this, the long-wave heating associated with cloud capping has been quantitatively estimated in an indirect way by employing an Advanced Research Weather Research and Forecasting (WRF-ARW) model version 2.2 developed by National Center for Atmospheric Research (NCAR), Colorado, USA, and supplementary data sets; and differentiated against other heating mechanisms. The present investigation as well establishes the potential of lidar remote-sensing technique in exploring some of the intriguing aspects of the cloud-environment relationship.

  13. Speech articulator measurements using low power EM-wave sensors

    SciTech Connect (OSTI)

    Holzrichter, J.F.; Burnett, G.C.; Ng, L.C.; Lea, W.A.

    1998-01-01

    Very low power electromagnetic (EM) wave sensors are being used to measure speech articulator motions as speech is produced. Glottal tissue oscillations, jaw, tongue, soft palate, and other organs have been measured. Previously, microwave imaging (e.g., using radar sensors) appears not to have been considered for such monitoring. Glottal tissue movements detected by radar sensors correlate well with those obtained by established laboratory techniques, and have been used to estimate a voiced excitation function for speech processing applications. The noninvasive access, coupled with the small size, low power, and high resolution of these new sensors, permit promising research and development applications in speech production, communication disorders, speech recognition and related topics. {copyright} {ital 1998 Acoustical Society of America.}

  14. Magnetohydrodynamic simulations of a jet drilling an H I cloud: Shock induced formation of molecular clouds and jet breakup

    SciTech Connect (OSTI)

    Asahina, Yuta; Ogawa, Takayuki; Matsumoto, Ryoji; Kawashima, Tomohisa; Furukawa, Naoko; Enokiya, Rei; Yamamoto, Hiroaki; Fukui, Yasuo

    2014-07-01

    The formation mechanism of the jet-aligned CO clouds found by NANTEN CO observations is studied by magnetohydrodynamical (MHD) simulations taking into account the cooling of the interstellar medium. Motivated by the association of the CO clouds with the enhancement of H I gas density, we carried out MHD simulations of the propagation of a supersonic jet injected into the dense H I gas. We found that the H I gas compressed by the bow shock ahead of the jet is cooled down by growth of the cooling instability triggered by the density enhancement. As a result, a cold dense sheath is formed around the interface between the jet and the H I gas. The radial speed of the cold, dense gas in the sheath is a few km s{sup 1} almost independent of the jet speed. Molecular clouds can be formed in this region. Since the dense sheath wrapping the jet reflects waves generated in the cocoon, the jet is strongly perturbed by the vortices of the warm gas in the cocoon, which breaks up the jet and forms a secondary shock in the H I-cavity drilled by the jet. The particle acceleration at the shock can be the origin of radio and X-ray filaments observed near the eastern edge of the W50 nebula surrounding the galactic jet source SS433.

  15. ASSIMILATION OF DOPPLER RADAR DATA INTO NUMERICAL WEATHER MODELS

    SciTech Connect (OSTI)

    Chiswell, S.; Buckley, R.

    2009-01-15

    During the year 2008, the United States National Weather Service (NWS) completed an eight fold increase in sampling capability for weather radars to 250 m resolution. This increase is expected to improve warning lead times by detecting small scale features sooner with increased reliability; however, current NWS operational model domains utilize grid spacing an order of magnitude larger than the radar data resolution, and therefore the added resolution of radar data is not fully exploited. The assimilation of radar reflectivity and velocity data into high resolution numerical weather model forecasts where grid spacing is comparable to the radar data resolution was investigated under a Laboratory Directed Research and Development (LDRD) 'quick hit' grant to determine the impact of improved data resolution on model predictions with specific initial proof of concept application to daily Savannah River Site operations and emergency response. Development of software to process NWS radar reflectivity and radial velocity data was undertaken for assimilation of observations into numerical models. Data values within the radar data volume undergo automated quality control (QC) analysis routines developed in support of this project to eliminate empty/missing data points, decrease anomalous propagation values, and determine error thresholds by utilizing the calculated variances among data values. The Weather Research and Forecasting model (WRF) three dimensional variational data assimilation package (WRF-3DVAR) was used to incorporate the QC'ed radar data into input and boundary conditions. The lack of observational data in the vicinity of SRS available to NWS operational models signifies an important data void where radar observations can provide significant input. These observations greatly enhance the knowledge of storm structures and the environmental conditions which influence their development. As the increase in computational power and availability has made higher resolution real-time model simulations possible, the need to obtain observations to both initialize numerical models and verify their output has become increasingly important. The assimilation of high resolution radar observations therefore provides a vital component in the development and utility of numerical model forecasts for both weather forecasting and contaminant transport, including future opportunities to improve wet deposition computations explicitly.

  16. Langasite Surface Acoustic Wave Sensors: Fabrication and Testing

    SciTech Connect (OSTI)

    Zheng, Peng; Greve, David W.; Oppenheim, Irving J.; Chin, Tao-Lun; Malone, Vanessa

    2012-02-01

    We report on the development of harsh-environment surface acoustic wave sensors for wired and wireless operation. Surface acoustic wave devices with an interdigitated transducer emitter and multiple reflectors were fabricated on langasite substrates. Both wired and wireless temperature sensing was demonstrated using radar-mode (pulse) detection. Temperature resolution of better than 0.5C was achieved between 200C and 600C. Oxygen sensing was achieved by depositing a layer of ZnO on the propagation path. Although the ZnO layer caused additional attenuation of the surface wave, oxygen sensing was accomplished at temperatures up to 700C. The results indicate that langasite SAW devices are a potential solution for harsh-environment gas and temperature sensing.

  17. Graphene based tunable fractal Hilbert curve array broadband radar absorbing screen for radar cross section reduction

    SciTech Connect (OSTI)

    Huang, Xianjun; Hu, Zhirun; Liu, Peiguo

    2014-11-15

    This paper proposes a new type of graphene based tunable radar absorbing screen. The absorbing screen consists of Hilbert curve metal strip array and chemical vapour deposition (CVD) graphene sheet. The graphene based screen is not only tunable when the chemical potential of the graphene changes, but also has broadband effective absorption. The absorption bandwidth is from 8.9GHz to 18.1GHz, ie., relative bandwidth of more than 68%, at chemical potential of 0eV, which is significantly wider than that if the graphene sheet had not been employed. As the chemical potential varies from 0 to 0.4eV, the central frequency of the screen can be tuned from 13.5GHz to 19.0GHz. In the proposed structure, Hilbert curve metal strip array was designed to provide multiple narrow band resonances, whereas the graphene sheet directly underneath the metal strip array provides tunability and averagely required surface resistance so to significantly extend the screen operation bandwidth by providing broadband impedance matching and absorption. In addition, the thickness of the screen has been optimized to achieve nearly the minimum thickness limitation for a nonmagnetic absorber. The working principle of this absorbing screen is studied in details, and performance under various incident angles is presented. This work extends applications of graphene into tunable microwave radar cross section (RCS) reduction applications.

  18. Quantifying Diurnal Cloud Radiative Effects by Cloud Type in the Tropical Western Pacific

    SciTech Connect (OSTI)

    Burleyson, Casey D.; Long, Charles N.; Comstock, Jennifer M.

    2015-06-01

    Cloud radiative effects are examined using long-term datasets collected at the three Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facilities in the tropical western Pacific. We quantify the surface radiation budget, cloud populations, and cloud radiative effects by partitioning the data by cloud type, time of day, and as a function of large scale modes of variability such as El Niño Southern Oscillation (ENSO) phase and wet/dry seasons at Darwin. The novel facet of our analysis is that we break aggregate cloud radiative effects down by cloud type across the diurnal cycle. The Nauru cloud populations and subsequently the surface radiation budget are strongly impacted by ENSO variability whereas the cloud populations over Manus only shift slightly in response to changes in ENSO phase. The Darwin site exhibits large seasonal monsoon related variations. We show that while deeper convective clouds have a strong conditional influence on the radiation reaching the surface, their limited frequency reduces their aggregate radiative impact. The largest source of shortwave cloud radiative effects at all three sites comes from low clouds. We use the observations to demonstrate that potential model biases in the amplitude of the diurnal cycle and mean cloud frequency would lead to larger errors in the surface energy budget compared to biases in the timing of the diurnal cycle of cloud frequency. Our results provide solid benchmarks to evaluate model simulations of cloud radiative effects in the tropics.

  19. ARM Cloud Aerosol Precipitation Experiment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Aerosol Precipitation Experiment a NOAA ship in the Pacific Ocean and on a DOE- sponsored plane over land and sea. These researchers will study: (1) water sources, evolution and structure of atmospheric rivers over the Pacific Ocean (2) long range transport of aerosols over the Pacific Ocean between Hawaii and the U.S. West Coast, and how aerosols interact with atmospheric rivers (3) the point where atmospheric rivers make landfall on the U.S. West Coast, especially how clouds form where

  20. Clouds, Aerosols and Precipitation in

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the Marine Boundary Layer (CAP-MBL) Graciosa Island, Azores, NE Atlantic Ocean Graciosa Island, Azores, NE Atlantic Ocean May 2009-December 2010 May 2009-December 2010 Rob Wood, University of Washington Rob Wood, University of Washington AMF Deployment Team Thanks to Mark Miller: AMF Site Scientist Mark Miller: AMF Site Scientist Kim Nitschke: AMF Site Manager CAP-MBL Proposal Team Importance of Low-Clouds for Climate Imperative that we understand the processes controlling the formation,

  1. Ultra wideband ground penetrating radar imaging of heterogeneous solids

    DOE Patents [OSTI]

    Warhus, John P. (Brentwood, CA); Mast, Jeffrey E. (Livermore, CA)

    1998-01-01

    A non-invasive imaging system for analyzing engineered structures comprises pairs of ultra wideband radar transmitters and receivers in a linear array that are connected to a timing mechanism that allows a radar echo sample to be taken at a variety of delay times for each radar pulse transmission. The radar transmitters and receivers are coupled to a position determining system that provides the x,y position on a surface for each group of samples measured for a volume from the surface. The radar transmitter and receivers are moved about the surface, e.g., attached to the bumper of a truck, to collect such groups of measurements from a variety of x,y positions. Return signal amplitudes represent the relative reflectivity of objects within the volume and the delay in receiving each signal echo represents the depth at which the object lays in the volume and the propagation speeds of the intervening material layers. Successively deeper z-planes are backward propagated from one layer to the next with an adjustment for variations in the expected propagation velocities of the material layers that lie between adjacent z-planes.

  2. Ultra wideband ground penetrating radar imaging of heterogeneous solids

    DOE Patents [OSTI]

    Warhus, J.P.; Mast, J.E.

    1998-11-10

    A non-invasive imaging system for analyzing engineered structures comprises pairs of ultra wideband radar transmitters and receivers in a linear array that are connected to a timing mechanism that allows a radar echo sample to be taken at a variety of delay times for each radar pulse transmission. The radar transmitters and receivers are coupled to a position determining system that provides the x,y position on a surface for each group of samples measured for a volume from the surface. The radar transmitter and receivers are moved about the surface, e.g., attached to the bumper of a truck, to collect such groups of measurements from a variety of x,y positions. Return signal amplitudes represent the relative reflectivity of objects within the volume and the delay in receiving each signal echo represents the depth at which the object lays in the volume and the propagation speeds of the intervening material layers. Successively deeper z-planes are backward propagated from one layer to the next with an adjustment for variations in the expected propagation velocities of the material layers that lie between adjacent z-planes. 11 figs.

  3. Predicting and validating the tracking of a Volcanic Ash Cloud during the 2006 Eruption of Mt. Augustine Volcano

    SciTech Connect (OSTI)

    Webley, Peter W.; Atkinson, D.; Collins, Richard L.; Dean, K.; Fochesatto, J.; Sassen, Kenneth; Cahill, Catherine F.; Prata, A.; Flynn, Connor J.; Mizutani, K.

    2008-11-01

    On 11 January 2006, Mount Augustine volcano in southern Alaska began erupting after 20-year repose. The Anchorage Forecast Office of the National Weather Service (NWS) issued an advisory on 28 January for Kodiak City. On 31 January, Alaska Airlines cancelled all flights to and from Anchorage after multiple advisories from the NWS for Anchorage and the surrounding region. The Alaska Volcano Observatory (AVO) had reported the onset of the continuous eruption. AVO monitors the approximately 100 active volcanoes in the Northern Pacific. Ash clouds from these volcanoes can cause serious damage to an aircraft and pose a serious threat to the local communities, and to transcontinental air traffic throughout the Arctic and sub-Arctic region. Within AVO, a dispersion model has been developed to track the dispersion of volcanic ash clouds. The model, Puff, was used operational by AVO during the Augustine eruptive period. Here, we examine the dispersion of a volcanic ash cloud from Mount Augustine across Alaska from 29 January through the 2 February 2006. We present the synoptic meteorology, the Puff predictions, and measurements from aerosol samplers, laser radar (or lidar) systems, and satellites. UAF aerosol samplers revealed the presence of volcanic aerosols at the surface at sites where Puff predicted the ash clouds movement. Remote sensing satellite data showed the development of the ash cloud in close proximity to the volcano and a sulfur-dioxide cloud further from the volcano consistent with the Puff predictions. Lidars showed the presence of volcanic aerosol with consistent characteristics aloft over Alaska and were capable of detecting the aerosol, even in the presence of scattered clouds and where the cloud is too thin/disperse to be detected by remote sensing satellite data. The lidar measurements revealed the different trajectories of ash consistent with the Puff predictions. Dispersion models provide a forecast of volcanic ash cloud movement that might be undetectable by any other means but are still a significant hazard. Validation is the key to assessing the accuracy of any future predictions. The study highlights the use of multiple and complementary observations used in detecting the trajectory ash cloud, both at the surface and aloft within the atmosphere.

  4. Potential application of the Motorola MSR-20 Radar to DOE site security

    SciTech Connect (OSTI)

    Arlowe, D.; Rebeil, P.; Vigil, R.

    1993-09-01

    This paper describes the results of testing the MSR-20 radar and provides guidance on how this radar may be used to provide early detection and warning of approaching intruders beyond DOE facility site boundaries.

  5. Wideband Waveform Design principles for Solid-state Weather Radars

    SciTech Connect (OSTI)

    Bharadwaj, Nitin; Chandrasekar, V.

    2012-01-01

    The use of solid-state transmitter is becoming a key part of the strategy to realize a network of low cost electronically steered radars. However, solid-state transmitters have low peak powers and this necessitates the use of pulse compression waveforms. In this paper a frequency diversity wideband waveforms design is proposed to mitigate low sensitivity of solid-state transmitters. In addition, the waveforms mitigate the range eclipsing problem associated with long pulse compression. An analysis of the performance of pulse compression using mismatched compression filters designed to minimize side lobe levels is presented. The impact of range side lobe level on the retrieval of Doppler moments are presented. Realistic simulations are performed based on CSU-CHILL radar data and Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) Integrated Project I (IP1) radar data.

  6. Tracking moving radar targets with parallel, velocity-tuned filters

    DOE Patents [OSTI]

    Bickel, Douglas L.; Harmony, David W.; Bielek, Timothy P.; Hollowell, Jeff A.; Murray, Margaret S.; Martinez, Ana

    2013-04-30

    Radar data associated with radar illumination of a movable target is processed to monitor motion of the target. A plurality of filter operations are performed in parallel on the radar data so that each filter operation produces target image information. The filter operations are defined to have respectively corresponding velocity ranges that differ from one another. The target image information produced by one of the filter operations represents the target more accurately than the target image information produced by the remainder of the filter operations when a current velocity of the target is within the velocity range associated with the one filter operation. In response to the current velocity of the target being within the velocity range associated with the one filter operation, motion of the target is tracked based on the target image information produced by the one filter operation.

  7. Interpretation of Synthetic Aperture Radar measurements of ocean currents

    SciTech Connect (OSTI)

    Rufenach, C.L.; Shuchman, R.A.; Lyzenga, D.R.

    1983-02-28

    Synthetic Aperture Radar (SAR) experiments hae been performed over the last few years to measure ocean currents inferred from shifts in the Doppler spectral peak. Interpretations of aircraft SAR measurements, when compared with limited surface values, tend to underestimate the currents by about 25%. A theory is developed that modifies the classical Doppler expression showing that the radar measurements are dependent on the radar processor (system) bandwidth and the received signal bandwidth. Measured bandwidths give a correction that increases the inferred current values by about 25%, bringing the measurements into good agreement. This new correction lends credence to the theory and increases the potential for application of SAR systems to future ocean current measurements. SAR measurements should include the determination of processor and signal bandwidths such that this correction can be applied.

  8. Storm Clouds Take Rain on Rollercoaster Ride

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Clouds Take Rain on Rollercoaster Ride For original submission and image(s), see ARM Research Highlights http://www.arm.gov/science/highlights/ Research Highlight Most of us think that when rain forms in a cloud, it will instantly fall down. That's what climate models typically assume, too. But in reality, rising plumes that form turbulent storm clouds can often carry raindrops, snowflakes, and even hailstones upward before they fall out. This lengthened journey prolongs their growth stage and

  9. A Global Cloud Resolving Model Goals

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Global Cloud Resolving Model Goals Uniform global horizontal grid spacing of 4 km or better ("cloud permitting") 100 or more layers up to at least the stratopause Parameterizations of microphysics, turbulence (including small clouds), and radiation Execution speed of at least several simulated days per wall-clock day on immediately available systems Annual cycle simulation by end of 2011. Motivations Parameterizations are still problematic. There are no spectral gaps. The equations

  10. Exploring Stratocumulus Cloud-Top Entrainment Processes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Stratocumulus Cloud-Top Entrainment Processes and Parameterizations by Using Doppler For original submission and image(s), see ARM Research Highlights http://www.arm.gov/science/highlights/ Research Highlight Stratocumulus clouds are a particularly important component of the Earth's climate system due to their large impact on the radiation budget. But the parameterization of entrainment in these clouds is yet to be fully resolved, which leads to uncertainties in numerical model forecasts ranging

  11. ARM - Measurement - Cloud particle number concentration

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    number concentration ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud particle number concentration The total number of cloud particles present in any given volume of air. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available

  12. ARM - Measurement - Cloud particle size distribution

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    size distribution ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud particle size distribution The number of cloud particles present in any given volume of air within a specified size range, including liquid and ice. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each

  13. Midlatitude Continental Convective Clouds Experiment Science Objective

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Midlatitude Continental Convective Clouds Experiment Science Objective Despite improvements in computing power, current weather and climate models are unable to accurately reproduce the formation, growth, and decay of clouds and precipitation associated with storm systems. Not only is this due to a lack of data about precipitation, but also about the 3-dimensional environment of the surrounding clouds, winds, and moisture, and how that affects the transfer of energy between the sun and Earth. To

  14. Interagency Field Test Evaluates Co-operation of Turbines and Radar |

    Office of Environmental Management (EM)

    Department of Energy Interagency Field Test Evaluates Co-operation of Turbines and Radar Interagency Field Test Evaluates Co-operation of Turbines and Radar May 1, 2012 - 2:56pm Addthis The Department of Energy and federal agency partners recently completed the first in a series of three radar technology field tests and demonstrations. The Interagency Field Test and Evaluation of Wind-Radar Mitigation Technologies is an $8 million demonstration initiative co-funded by the Energy Department,

  15. Long-term Observations of the Convective Boundary Layer Using Insect Radar Returns at the SGP ARM Climate Research Facility

    SciTech Connect (OSTI)

    Chandra, A S; Kollias, P; Giangrande, S E; Klein, S A

    2009-08-20

    A long-term study of the turbulent structure of the convective boundary layer (CBL) at the U.S. Department of Energy Atmospheric Radiation Measurement Program (ARM) Southern Great Plains (SGP) Climate Research Facility is presented. Doppler velocity measurements from insects occupying the lowest 2 km of the boundary layer during summer months are used to map the vertical velocity component in the CBL. The observations cover four summer periods (2004-08) and are classified into cloudy and clear boundary layer conditions. Profiles of vertical velocity variance, skewness, and mass flux are estimated to study the daytime evolution of the convective boundary layer during these conditions. A conditional sampling method is applied to the original Doppler velocity dataset to extract coherent vertical velocity structures and to examine plume dimension and contribution to the turbulent transport. Overall, the derived turbulent statistics are consistent with previous aircraft and lidar observations. The observations provide unique insight into the daytime evolution of the convective boundary layer and the role of increased cloudiness in the turbulent budget of the subcloud layer. Coherent structures (plumes-thermals) are found to be responsible for more than 80% of the total turbulent transport resolved by the cloud radar system. The extended dataset is suitable for evaluating boundary layer parameterizations and testing large-eddy simulations (LESs) for a variety of surface and cloud conditions.

  16. Homodyne impulse radar hidden object locator

    DOE Patents [OSTI]

    McEwan, T.E.

    1996-04-30

    An electromagnetic detector is designed to locate an object hidden behind a separator or a cavity within a solid object. The detector includes a PRF generator for generating 2 MHz pulses, a homodyne oscillator for generating a 2 kHz square wave, and for modulating the pulses from the PRF generator. A transmit antenna transmits the modulated pulses through the separator, and a receive antenna receives the signals reflected off the object. The receiver path of the detector includes a sample and hold circuit, an AC coupled amplifier which filters out DC bias level shifts in the sample and hold circuit, and a rectifier circuit connected to the homodyne oscillator and to the AC coupled amplifier, for synchronously rectifying the modulated pulses transmitted over the transmit antenna. The homodyne oscillator modulates the signal from the PRF generator with a continuous wave (CW) signal, and the AC coupled amplifier operates with a passband centered on that CW signal. The present detector can be used in several applications, including the detection of metallic and non-metallic objects, such as pipes, studs, joists, nails, rebars, conduits and electrical wiring, behind wood wall, ceiling, plywood, particle board, dense hardwood, masonry and cement structure. The detector is portable, light weight, simple to use, inexpensive, and has a low power emission which facilitates the compliance with Part 15 of the FCC rules. 15 figs.

  17. Homodyne impulse radar hidden object locator

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1996-01-01

    An electromagnetic detector is designed to locate an object hidden behind a separator or a cavity within a solid object. The detector includes a PRF generator for generating 2 MHz pulses, a homodyne oscillator for generating a 2 kHz square wave, and for modulating the pulses from the PRF generator. A transmit antenna transmits the modulated pulses through the separator, and a receive antenna receives the signals reflected off the object. The receiver path of the detector includes a sample and hold circuit, an AC coupled amplifier which filters out DC bias level shifts in the sample and hold circuit, and a rectifier circuit connected to the homodyne oscillator and to the AC coupled amplifier, for synchronously rectifying the modulated pulses transmitted over the transmit antenna. The homodyne oscillator modulates the signal from the PRF generator with a continuous wave (CW) signal, and the AC coupled amplifier operates with a passband centered on that CW signal. The present detector can be used in several applications, including the detection of metallic and non-metallic objects, such as pipes, studs, joists, nails, rebars, conduits and electrical wiring, behind wood wall, ceiling, plywood, particle board, dense hardwood, masonry and cement structure. The detector is portable, light weight, simple to use, inexpensive, and has a low power emission which facilitates the compliance with Part 15 of the FCC rules.

  18. ARM - Field Campaign - Fall 1997 Cloud IOP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govCampaignsFall 1997 Cloud IOP ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Fall 1997 Cloud IOP 1997.09.15 - 1997.10.05 Lead Scientist : Gerald Mace For data sets, see below. Summary The primary objective of the Cloud IOP was to generate a multi-platform data set that can be used as validation for cloud property retrieval algorithms that are being implemented on the operational MMCR data stream.

  19. Ground-based Microwave Cloud Tomography

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Microwave Cloud Tomography Experiment, SGP, May 15-June 15, 2009 Lead Scientist Dong Huang, BNL Co-Investigators Al Gasiewski, UC Boulder Maria Cadeddu, ANL Warren Wiscombe, BNL Radiation Processes Working Group March 30, 2009 multiple radiometers All good cloud radiation modelers should close their airplane window shades so as not to be corrupted by the spectacle of real 3D clouds. - Roger Davies In case you forget to do this, you see 3/30/2009 ARM RPWG 2 Effects of cloud structure on radiation

  20. RACORO continental boundary layer cloud investigations. Part...

    Office of Scientific and Technical Information (OSTI)

    RACORO continental boundary layer cloud investigations. Part I: Case study development and ensemble large-scale forcings Citation Details In-Document Search This content will ...

  1. ARM - Field Campaign - Spring Cloud IOP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    respectively. From these measurements, cloud condensed water content (CVIcwc) and number concentration (CVInum) are determined. CVInum may be artificially enhanced due to breakup...

  2. What Makes Clouds Form, Grow and Die?

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    were born and grew. Those formulas did not always reflect reality. With more advanced computers came the ability to explicitly simulate large-cloud systems instead of approximating...

  3. Mountain-induced Dynamics Influence Cloud Phase

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2010-2011 via coordinated projects targeting clouds, precipitation, and dynamics in the Park Range of Colorado. The National Science Foundation sponsored aircraft measurements as...

  4. Fragmentation in rotating isothermal protostellar clouds

    SciTech Connect (OSTI)

    Bodenheimer, P.; Tohline, J.E.; Black, D.C.

    1980-01-01

    Results of an extensive set of 3-D hydrodynamic calculations that have been performed to investigate the susceptibility of rotating clouds to gravitational fragmentation are presented. (GHT)

  5. Characterizing Arctic Mixed-phase Cloud Structure

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    have two distinguished cloud base heights (CBHs) that can be defined by both ceilometer (black dots) and micropulse lidar (MPL; pink dots) measurements (Figure 1). For a...

  6. DOE Research and Development Accomplishments Tag Cloud

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Database Tag Cloud This tag cloud is a specific type of weighted list that provides a quick look at the content of the DOE R&D Accomplishments database. It can be easily browsed because terms are in alphabetical order. With this tag cloud, there is a direct correlation between font size and quantity. The more times a term appears in the bibliographic citations, the larger the font size. This tag cloud is also interactive. Clicking on a term will activate a search for that term. Search

  7. CHARACTERIZATION OF CLOUDS IN TITAN'S TROPICAL ATMOSPHERE

    SciTech Connect (OSTI)

    Griffith, Caitlin A.; Penteado, Paulo; Rodriguez, Sebastien; Baines, Kevin H.; Buratti, Bonnie; Sotin, Christophe; Clark, Roger; Nicholson, Phil; Jaumann, Ralf

    2009-09-10

    Images of Titan's clouds, possible over the past 10 years, indicate primarily discrete convective methane clouds near the south and north poles and an immense stratiform cloud, likely composed of ethane, around the north pole. Here we present spectral images from Cassini's Visual Mapping Infrared Spectrometer that reveal the increasing presence of clouds in Titan's tropical atmosphere. Radiative transfer analyses indicate similarities between summer polar and tropical methane clouds. Like their southern counterparts, tropical clouds consist of particles exceeding 5 {mu}m. They display discrete structures suggestive of convective cumuli. They prevail at a specific latitude band between 8 deg. - 20 deg. S, indicative of a circulation origin and the beginning of a circulation turnover. Yet, unlike the high latitude clouds that often reach 45 km altitude, these discrete tropical clouds, so far, remain capped to altitudes below 26 km. Such low convective clouds are consistent with the highly stable atmospheric conditions measured at the Huygens landing site. Their characteristics suggest that Titan's tropical atmosphere has a dry climate unlike the south polar atmosphere, and despite the numerous washes that carve the tropical landscape.

  8. ARM - Field Campaign - Midlatitude Continental Convective Clouds...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Experiment (MC3E) Campaign Links Science Plan MC3E Website Field Campaign Report ARM Data Discovery Browse Data Related Campaigns Midlatitude Continental Convective Clouds...

  9. The LANL Cloud-Aerosol Model

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    that incorporates two unique aspects in its formulation. First, the model employs a nonlinear solver that requires cloud-aerosol parameterizations be smooth or contain reasonable...

  10. An Analysis of Cloud Absorption During

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Analysis of Cloud Absorption During ARESE II (Spring 2000) D. M. Powell, R. T. Marchand, and T. P. Ackerman Pacific Northwest National Laboratory Richland, Washington Introduction...

  11. ARM - Evaluation Product - Cloud Classification VAP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    properties includes cloud boundaries, thickness, phase, type, and precipitation information, and hence provides a useful tool for evaluation of model simulations and...

  12. Dynamics of Molecular Clouds: Observations, Simulations, and...

    Office of Scientific and Technical Information (OSTI)

    Simulations, and NIF Experiments Citation Details In-Document Search Title: Dynamics of Molecular Clouds: Observations, Simulations, and NIF Experiments Authors: Kane, J ...

  13. GIANT MOLECULAR CLOUDS AND STAR FORMATION IN THE NON-GRAND DESIGN SPIRAL GALAXY NGC 6946

    SciTech Connect (OSTI)

    Rebolledo, David; Wong, Tony; Leroy, Adam; Koda, Jin; Meyer, Jennifer Donovan

    2012-10-01

    We present high spatial resolution observations of giant molecular clouds (GMCs) in the eastern part of the nearby spiral galaxy NGC 6946 obtained with the Combined Array for Research in Millimeter-wave Astronomy (CARMA). We have observed CO(1 {yields} 0), CO(2 {yields} 1) and {sup 13}CO(1 {yields} 0), achieving spatial resolutions of 5.''4 Multiplication-Sign 5.''0, 2.''5 Multiplication-Sign 2.''0, and 5.''6 Multiplication-Sign 5.''4, respectively, over a region of 6 Multiplication-Sign 6 kpc. This region extends from 1.5 kpc to 8 kpc galactocentric radius, thus avoiding the intense star formation in the central kpc. We have recovered short-spacing u-v components by using single dish observations from the Nobeyama 45 m and IRAM 30 m telescopes. Using the automated CPROPS algorithm, we identified 45 CO cloud complexes in the CO(1 {yields} 0) map and 64 GMCs in the CO(2 {yields} 1) maps. The sizes, line widths, and luminosities of the GMCs are similar to values found in other extragalactic studies. We have classified the clouds into on-arm and inter-arm clouds based on the stellar mass density traced by the 3.6 {mu}m map. Clouds located on-arm present in general higher star formation rates than clouds located in inter-arm regions. Although the star formation efficiency shows no systematic trend with galactocentric radius, some on-arm clouds-which are more luminous and more massive compared to inter-arm GMCs-are also forming stars more efficiently than the rest of the identified GMCs. We find that these structures appear to be located in two specific regions in the spiral arms. One of them shows a strong velocity gradient, suggesting that this region of high star formation efficiency may be the result of gas flow convergence.

  14. Electron Cloud Effects in Accelerators

    SciTech Connect (OSTI)

    Furman, M.A.

    2012-11-30

    Abstract We present a brief summary of various aspects of the electron-cloud effect (ECE) in accelerators. For further details, the reader is encouraged to refer to the proceedings of many prior workshops, either dedicated to EC or with significant EC contents, including the entire ?ECLOUD? series [1?22]. In addition, the proceedings of the various flavors of Particle Accelerator Conferences [23] contain a large number of EC-related publications. The ICFA Beam Dynamics Newsletter series [24] contains one dedicated issue, and several occasional articles, on EC. An extensive reference database is the LHC website on EC [25].

  15. Detonation Wave Profile

    SciTech Connect (OSTI)

    Menikoff, Ralph

    2015-12-14

    The Zel’dovich-von Neumann-Doering (ZND) profile of a detonation wave is derived. Two basic assumptions are required: i. An equation of state (EOS) for a partly burned explosive; P(V, e, λ). ii. A burn rate for the reaction progress variable; d/dt λ = R(V, e, λ). For a steady planar detonation wave the reactive flow PDEs can be reduced to ODEs. The detonation wave profile can be determined from an ODE plus algebraic equations for points on the partly burned detonation loci with a specified wave speed. Furthermore, for the CJ detonation speed the end of the reaction zone is sonic. A solution to the reactive flow equations can be constructed with a rarefaction wave following the detonation wave profile. This corresponds to an underdriven detonation wave, and the rarefaction is know as a Taylor wave.

  16. Intercomparison of model simulations of mixed-phase clouds observed...

    Office of Scientific and Technical Information (OSTI)

    Radiation Measurement (ARM) program's Mixed-Phase Arctic Cloud Experiment. The observed cloud occurred in a well-mixed boundary layer with a cloud top temperature of -15 C. The ...

  17. Catching a Wave: Innovative Wave Energy Device Surfs for Power...

    Office of Environmental Management (EM)

    Catching a Wave: Innovative Wave Energy Device Surfs for Power in Hawaii Catching a Wave: Innovative Wave Energy Device Surfs for Power in Hawaii July 29, 2015 - 12:00pm Addthis...

  18. RADAR OBSERVATIONS OF COMET 103P/HARTLEY 2

    SciTech Connect (OSTI)

    Harmon, John K.; Nolan, Michael C.; Howell, Ellen S.; Taylor, Patrick A.; Giorgini, Jon D.

    2011-06-10

    Comets rarely come close enough to be studied intensively with Earth-based radar. The most recent such occurrence was when Comet 103P/Hartley 2 passed within 0.12 AU in late 2010 October, less than two weeks before the EPOXI flyby. This offered a unique opportunity to improve pre-encounter trajectory knowledge and obtain complementary physical data for a spacecraft-targeted comet. 103P/Hartley 2 is only the fourth comet nucleus to be imaged with radar and already the second to be identified as an elongated, bilobate object based on its delay-Doppler signature. The images show the dominant spin mode to be a rotation about the short axis with a period of 18.2 hr. The nucleus has a low radar albedo consistent with a surface density of 0.5-1.0 g cm{sup -3}. A separate echo component was detected from large (>cm) grains ejected anisotropically with velocities of several to tens of meters per second. Radar shows that, in terms of large-grain production, 103P/Hartley 2 is an unusually active comet for its size.

  19. Generating nonlinear FM chirp radar signals by multiple integrations

    DOE Patents [OSTI]

    Doerry, Armin W. (Albuquerque, NM)

    2011-02-01

    A phase component of a nonlinear frequency modulated (NLFM) chirp radar pulse can be produced by performing digital integration operations over a time interval defined by the pulse width. Each digital integration operation includes applying to a respectively corresponding input parameter value a respectively corresponding number of instances of digital integration.

  20. The Sensitivity of Radiative Fluxes to Parameterized Cloud Microphysic...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    these fields include cloud altitude, cloud amount, liquid and ice content, particle size spectra, and radiative fluxes at the surface and the TOA. Comparisons with Atmospheric...

  1. ARM - Field Campaign - Azores: Clouds, Aerosol and Precipitation...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Campaigns Azores: Above-Cloud Radiation Budget near Graciosa Island 2010.04.15, Miller, AMF Azores: Extension to Clouds, Aerosol and Precipitation in the Marine Boundary...

  2. City of Red Cloud, Nebraska (Utility Company) | Open Energy Informatio...

    Open Energy Info (EERE)

    Red Cloud, Nebraska (Utility Company) Jump to: navigation, search Name: Red Cloud Municipal Power Place: Nebraska Phone Number: 402-746-2215 Website: www.redcloudnebraska.comgover...

  3. BALTEX BRIDGE cloud liquid water network project: CLIWA-NET

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    cloud types 432008 ARM-08 (Simplified) Working Strategy of GCSS Large Eddy Simulation (LES) Models Cloud Resolving Models (CRM) Single Column Model Versions of Climate Models...

  4. Direct Numerical Simulations and Robust Predictions of Cloud...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    cloud. Credit: Computational Science and Engineering Laboratory, ETH Zurich, Switzerland Direct Numerical Simulations and Robust Predictions of Cloud Cavitation Collapse PI Name:...

  5. ARM - Field Campaign - Marine ARM GPCI Investigation of Clouds...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govCampaignsMarine ARM GPCI Investigation of Clouds (MAGIC) Campaign Links MAGIC Website ARM Data Discovery Browse Data Related Campaigns Marine ARM GPCI Investigation of Clouds...

  6. ARM - Field Campaign - Biogenic Aerosols - Effects on Clouds...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    relevant to DOE's goals in understanding the impact of clouds and aerosols on climate change. TWST contributes significantly to the body of data used for extracting cloud...

  7. Can Cloud Computing Address the Scientific Computing Requirements...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    achieve energy efficiency levels comparable to commercial cloud centers. Cloud is a business model and can be applied at DOE supercomputing centers. The progress of the...

  8. Assessing Cloud Spatial and Vertical Distribution with Infrared...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    on assessing cloud spatial and vertical distribution with a recently developed infrared (IR) cloud analyzer, named Nephelo. The experiment took place at the ARM's central facility,...

  9. Summary of workshop session F on electron-cloud instabilities...

    Office of Scientific and Technical Information (OSTI)

    Conference: Summary of workshop session F on electron-cloud instabilities Citation Details In-Document Search Title: Summary of workshop session F on electron-cloud instabilities ...

  10. Wave Energy | Open Energy Information

    Open Energy Info (EERE)

    Wave Energy Jump to: navigation, search Contents 1 Description 2 History 3 Technology 4 Current and Possible Wave Farms 5 Pros and Cons Description Wave energy (or wave power) is...

  11. Parameterizations of Cloud Microphysics and Indirect Aerosol Effects

    SciTech Connect (OSTI)

    Tao, Wei-Kuo

    2014-05-19

    1. OVERVIEW Aerosols and especially their effect on clouds are one of the key components of the climate system and the hydrological cycle [Ramanathan et al., 2001]. Yet, the aerosol effect on clouds remains largely unknown and the processes involved not well understood. A recent report published by the National Academy of Science states "The greatest uncertainty about the aerosol climate forcing - indeed, the largest of all the uncertainties about global climate forcing - is probably the indirect effect of aerosols on clouds [NRC, 2001]." The aerosol effect on clouds is often categorized into the traditional "first indirect (i.e., Twomey)" effect on the cloud droplet sizes for a constant liquid water path [Twomey, 1977] and the "semi-direct" effect on cloud coverage [e.g., Ackerman et al., 2000]. Enhanced aerosol concentrations can also suppress warm rain processes by producing a narrow droplet spectrum that inhibits collision and coalescence processes [e.g., Squires and Twomey, 1961; Warner and Twomey, 1967; Warner, 1968; Rosenfeld, 1999]. The aerosol effect on precipitation processes, also known as the second type of aerosol indirect effect [Albrecht, 1989], is even more complex, especially for mixed-phase convective clouds. Table 1 summarizes the key observational studies identifying the microphysical properties, cloud characteristics, thermodynamics and dynamics associated with cloud systems from high-aerosol continental environments. For example, atmospheric aerosol concentrations can influence cloud droplet size distributions, warm-rain process, cold-rain process, cloud-top height, the depth of the mixed phase region, and occurrence of lightning. In addition, high aerosol concentrations in urban environments could affect precipitation variability by providing an enhanced source of cloud condensation nuclei (CCN). Hypotheses have been developed to explain the effect of urban regions on convection and precipitation [van den Heever and Cotton, 2007 and Shepherd, 2005]. Recently, a detailed spectral-bin microphysical scheme was implemented into the Goddard Cumulus Ensemble (GCE) model. Atmospheric aerosols are also described using number density size-distribution functions. A spectral-bin microphysical model is very expensive from a computational point of view and has only been implemented into the 2D version of the GCE at the present time. The model is tested by studying the evolution of deep tropical clouds in the west Pacific warm pool region and summertime convection over a mid-latitude continent with different concentrations of CCN: a low "clean" concentration and a high "dirty" concentration. The impact of atmospheric aerosol concentration on cloud and precipitation will be investigated. 2. MODEL DESCRIPTION AND CASE STUDIES 2.1 GCE MODEL The model used in this study is the 2D version of the GCE model. Modeled flow is anelastic. Second- or higher-order advection schemes can produce negative values in the solution. Thus, a Multi-dimensional Positive Definite Advection Transport Algorithm (MPDATA) has been implemented into the model. All scalar variables (potential temperature, water vapor, turbulent coefficient and all five hydrometeor classes) use forward time differencing and the MPDATA for advection. Dynamic variables, u, v and w, use a second-order accurate advection scheme and a leapfrog time integration (kinetic energy semi-conserving method). Short-wave (solar) and long-wave radiation as well as a subgrid-scale TKE turbulence scheme are also included in the model. Details of the model can be found in Tao and Simpson (1993) and Tao et al. (2003). 2.2 Microphysics (Bin Model) The formulation of the explicit spectral-bin microphysical processes is based on solving stochastic kinetic equations for the size distribution functions of water droplets (cloud droplets and raindrops), and six types of ice particles: pristine ice crystals (columnar and plate-like), snow (dendrites and aggregates), graupel and frozen drops/hail. Each type is described by a special size distribution function containing 33 categories (bins). Atmospheric aerosols are also described using number density size-distribution functions (containing 33 bins). Droplet nucleation (activation) is derived from the analytical calculation of super-saturation, which is used to determine the sizes of aerosol particles to be activated and the corresponding sizes of nucleated droplets. Primary nucleation of each type of ice crystal takes place within certain temperature ranges. A detailed description of these explicitly parameterized processes can be found in Khain and Sednev (1996) and Khain et al. (1999, 2001). 2.3 Case Studies Three cases, a tropical oceanic squall system observed during TOGA COARE (Tropical Ocean and Global Atmosphere Coupled Ocean-Atmosphere Response Experiment, which occurred over the Pacific Ocean warm pool from November 1992 to February 1993), a midlatitude continental squall system observed during PRESTORM (Preliminary Regional Experiment for STORM-Central, which occurred in Kansas and Oklahoma during May-June 1985), and mid-afternoon convection observed during CRYSTAL-FACE (Cirrus Regional Study of Tropical Anvils and Cirrus Layers – Florida Area Cumulus Experiment, which occurred in Florida during July 2002), will be used to examine the impact of aerosols on deep, precipitating systems. 3. SUMMARY of RESULTS • For all three cases, higher CCN produces smaller cloud droplets and a narrower spectrum. Dirty conditions delay rain formation, increase latent heat release above the freezing level, and enhance vertical velocities at higher altitude for all cases. Stronger updrafts, deeper mixed-phase regions, and more ice particles are simulated with higher CCN in good agreement with observations. • In all cases, rain reaches the ground early with lower CCN. Rain suppression is also evident in all three cases with high CCN in good agreement with observations (Rosenfeld, 1999, 2000 and others). Rain suppression, however, only occurs during the first hour of simulation. This result suggests that microphysical processes dominate the impact of aerosols on precipitation in the early stage of precipitation development. • During the mature stage of the simulations, the effect of increasing aerosol concentration ranges from rain suppression in the PRESTORM case to little effect on surface rainfall in the CRYSTAL-FACE case to rain enhancement in the TOGA COARE case. • The model results suggest that evaporative cooling is a key process in determining whether higher CCN reduces or enhances precipitation. Cold pool strength can be enhanced by stronger evaporation. When cold pool interacts with the near surface wind shear, the low-level convergence can be stronger, facilitating secondary cloud formation and more vigorous precipitation processes. Evaporative cooling is more than two times stronger at low levels with higher CCN for the TOGA COARE case during the early stages of precipitation development. However, evaporative cooling is slightly stronger at lower levels with lower CCN for the PRESTORM case. The early formation of rain in the clean environment could allow for the formation of an earlier and stronger cold pool compared to a dirty environment. PRESTORM has a very dry environment and both large and small rain droplets can evaporate. Consequently, the cold pool is relatively weaker, and the system is relatively less intense with higher CCN. • Sensitivity tests are conducted to determine the impact of ice processes on aerosol-precipitation interaction. The results suggested that ice processes are crucial for suppressing precipitation due to high CCN for the PRESTORM case. More and smaller ice particles are generated in the dirty case and transported to the trailing stratiform region. This reduces the heavy convective rain and contributes to the weakening of the cold pool. Warm rain processes dominate the TOGA COARE case. Therefore, ice processes only play a secondary role in terms of aerosol-precipitation interaction. • Two of the three cloud systems presented in this paper formed a line structure (squall system). A 2D simulation, therefore, gives a good approximation to such a line of convective clouds. Since the real atmosphere is 3D, further 3D cloud-resolving simulations are needed to address aerosol-precipitation interactions. 4. REFERENCES Tao, W.-K., X. Li, A. Khain, T. Matsui, S. Lang, and J. Simpson, 2007: The role of atmospheric aerosol concentration on deep convective precipitation: Cloud-resolving model simulations. J. Geophy. Res., 112, D24S18, doi:10.1029/2007JD008728. All other references can be found in above paper. 5. Acknowledgements The GCE model is mainly supported by the NASA Headquarters Atmospheric Dynamics and Thermodynamics Program and the NASA Tropical Rainfall Measuring Mission (TRMM). The research was also supported by the Office of Science (BER), U. S. Department of Energy/Atmospheric Radiation Measurement (DOE/ARM) Interagency. The authors acknowledge NASA Goddard Space Flight Center for computer time used in this research.

  12. ARM - Midlatitude Continental Convective Clouds

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jensen, Mike; Bartholomew, Mary Jane; Genio, Anthony Del; Giangrande, Scott; Kollias, Pavlos

    2012-01-19

    Convective processes play a critical role in the Earth's energy balance through the redistribution of heat and moisture in the atmosphere and their link to the hydrological cycle. Accurate representation of convective processes in numerical models is vital towards improving current and future simulations of Earths climate system. Despite improvements in computing power, current operational weather and global climate models are unable to resolve the natural temporal and spatial scales important to convective processes and therefore must turn to parameterization schemes to represent these processes. In turn, parameterization schemes in cloud-resolving models need to be evaluated for their generality and application to a variety of atmospheric conditions. Data from field campaigns with appropriate forcing descriptors have been traditionally used by modelers for evaluating and improving parameterization schemes.

  13. ARM - Midlatitude Continental Convective Clouds

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jensen, Mike; Bartholomew, Mary Jane; Genio, Anthony Del; Giangrande, Scott; Kollias, Pavlos

    Convective processes play a critical role in the Earth's energy balance through the redistribution of heat and moisture in the atmosphere and their link to the hydrological cycle. Accurate representation of convective processes in numerical models is vital towards improving current and future simulations of Earths climate system. Despite improvements in computing power, current operational weather and global climate models are unable to resolve the natural temporal and spatial scales important to convective processes and therefore must turn to parameterization schemes to represent these processes. In turn, parameterization schemes in cloud-resolving models need to be evaluated for their generality and application to a variety of atmospheric conditions. Data from field campaigns with appropriate forcing descriptors have been traditionally used by modelers for evaluating and improving parameterization schemes.

  14. Modeling Incoherent Electron Cloud Effects

    SciTech Connect (OSTI)

    Vay, Jean-Luc; Benedetto, E.; Fischer, W.; Franchetti, G.; Ohmi, K.; Schulte, D.; Sonnad, K.; Tomas, R.; Vay, J.-L.; Zimmermann, F.; Rumolo, G.; Pivi, M.; Raubenheimer, T.

    2007-06-18

    Incoherent electron effects could seriously limit the beam lifetime in proton or ion storage rings, such as LHC, SPS, or RHIC, or blow up the vertical emittance of positron beams, e.g., at the B factories or in linear-collider damping rings. Different approaches to modeling these effects each have their own merits and drawbacks. We describe several simulation codes which simplify the descriptions of the beam-electron interaction and of the accelerator structure in various different ways, and present results for a toy model of the SPS. In addition, we present evidence that for positron beams the interplay of incoherent electron-cloud effects and synchrotron radiation can lead to a significant increase in vertical equilibrium emittance. The magnitude of a few incoherent e+e- scattering processes is also estimated. Options for future code development are reviewed.

  15. ARM - Facility News Article

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Battle With Bugs Nearly Over Thanks to New Radar Bookmark and Share The new W-band ARM cloud radar, or WACR, provides improved sensitivity for detecting tiny objects in the atmosphere to an altitude of 5 km. The instrument's antenna is located adjacent to the [/instruments/instrument.php?id=mmcr][millimeter wave cloud radar (MMCR)] antenna on top of the MMCR shelter; the rest of the unit is located inside (inset). The main purpose of the millimeter wavelength cloud radar (MMCR) is to measure

  16. Photolysis rates in correlated overlapping cloud fields: Cloud-J 7.3

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Prather, M. J.

    2015-05-27

    A new approach for modeling photolysis rates (J values) in atmospheres with fractional cloud cover has been developed and implemented as Cloud-J – a multi-scattering eight-stream radiative transfer model for solar radiation based on Fast-J. Using observed statistics for the vertical correlation of cloud layers, Cloud-J 7.3 provides a practical and accurate method for modeling atmospheric chemistry. The combination of the new maximum-correlated cloud groups with the integration over all cloud combinations represented by four quadrature atmospheres produces mean J values in an atmospheric column with root-mean-square errors of 4% or less compared with 10–20% errors using simpler approximations. Cloud-Jmore » is practical for chemistry-climate models, requiring only an average of 2.8 Fast-J calls per atmosphere, vs. hundreds of calls with the correlated cloud groups, or 1 call with the simplest cloud approximations. Another improvement in modeling J values, the treatment of volatile organic compounds with pressure-dependent cross sections is also incorporated into Cloud-J.« less

  17. Photolysis rates in correlated overlapping cloud fields: Cloud-J 7.3c

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Prather, M. J.

    2015-08-14

    A new approach for modeling photolysis rates (J values) in atmospheres with fractional cloud cover has been developed and is implemented as Cloud-J – a multi-scattering eight-stream radiative transfer model for solar radiation based on Fast-J. Using observations of the vertical correlation of cloud layers, Cloud-J 7.3c provides a practical and accurate method for modeling atmospheric chemistry. The combination of the new maximum-correlated cloud groups with the integration over all cloud combinations by four quadrature atmospheres produces mean J values in an atmospheric column with root mean square (rms) errors of 4 % or less compared with 10–20 % errorsmore » using simpler approximations. Cloud-J is practical for chemistry–climate models, requiring only an average of 2.8 Fast-J calls per atmosphere vs. hundreds of calls with the correlated cloud groups, or 1 call with the simplest cloud approximations. Another improvement in modeling J values, the treatment of volatile organic compounds with pressure-dependent cross sections, is also incorporated into Cloud-J.« less

  18. Cycloidal Wave Energy Converter

    SciTech Connect (OSTI)

    Stefan G. Siegel, Ph.D.

    2012-11-30

    This program allowed further advancing the development of a novel type of wave energy converter, a Cycloidal Wave Energy Converter or CycWEC. A CycWEC consists of one or more hydrofoils rotating around a central shaft, and operates fully submerged beneath the water surface. It operates under feedback control sensing the incoming waves, and converts wave power to shaft power directly without any intermediate power take off system. Previous research consisting of numerical simulations and two dimensional small 1:300 scale wave flume experiments had indicated wave cancellation efficiencies beyond 95%. The present work was centered on construction and testing of a 1:10 scale model and conducting two testing campaigns in a three dimensional wave basin. These experiments allowed for the first time for direct measurement of electrical power generated as well as the interaction of the CycWEC in a three dimensional environment. The Atargis team successfully conducted two testing campaigns at the Texas A&M Offshore Technology Research Center and was able to demonstrate electricity generation. In addition, three dimensional wave diffraction results show the ability to achieve wave focusing, thus increasing the amount of wave power that can be extracted beyond what was expected from earlier two dimensional investigations. Numerical results showed wave cancellation efficiencies for irregular waves to be on par with results for regular waves over a wide range of wave lengths. Using the results from previous simulations and experiments a full scale prototype was designed and its performance in a North Atlantic wave climate of average 30kW/m of wave crest was estimated. A full scale WEC with a blade span of 150m will deliver a design power of 5MW at an estimated levelized cost of energy (LCOE) in the range of 10-17 US cents per kWh. Based on the new results achieved in the 1:10 scale experiments these estimates appear conservative and the likely performance at full scale will exceed this initial performance estimates. In advancing the Technology Readiness Level (TRL) of this type of wave energy converter from 3 to 4, we find the CycWEC to exceed our initial estimates in terms of hydrodynamic performance. Once fully developed and optimized, it has the potential to not just outperform all other WEC technologies, but to also deliver power at a lower LCOE than competing conventional renewables like wind and solar. Given the large wave power resource both domestically and internationally, this technology has the potential to lead to a large improvement in our ability to produce clean electricity at affordable cost.

  19. ARM - Publications: Science Team Meeting Documents

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Characterizating Stratiform Clouds Variability from Millimeter-Wave Radar Data Kogan, Z.N.(a), Mechem, D.B.(b), and Kogan, Y.L.(c), Cooperative Institute for Mesoscale...

  20. Methods And System Suppressing Clutter In A Gain-Block, Radar-Responsive Tag System

    DOE Patents [OSTI]

    Ormesher, Richard C. (Albuquerque, NM); Axline, Robert M. (Albuquerque, NM)

    2006-04-18

    Methods and systems reduce clutter interference in a radar-responsive tag system. A radar transmits a series of linear-frequency-modulated pulses and receives echo pulses from nearby terrain and from radar-responsive tags that may be in the imaged scene. Tags in the vicinity of the radar are activated by the radar's pulses. The tags receive and remodulate the radar pulses. Tag processing reverses the direction, in time, of the received waveform's linear frequency modulation. The tag retransmits the remodulated pulses. The radar uses a reversed-chirp de-ramp pulse to process the tag's echo. The invention applies to radar systems compatible with coherent gain-block tags. The invention provides a marked reduction in the strength of residual clutter echoes on each and every echo pulse received by the radar. SAR receiver processing effectively whitens passive-clutter signatures across the range dimension. Clutter suppression of approximately 14 dB is achievable for a typical radar system.

  1. Nonlinear automatic landing control of unmanned aerial vehicles on moving platforms via a 3D laser radar

    SciTech Connect (OSTI)

    Hervas, Jaime Rubio; Tang, Hui; Reyhanoglu, Mahmut

    2014-12-10

    This paper presents a motion tracking and control system for automatically landing Unmanned Aerial Vehicles (UAVs) on an oscillating platform using Laser Radar (LADAR) observations. The system itself is assumed to be mounted on a ship deck. A full nonlinear mathematical model is first introduced for the UAV. The ship motion is characterized by a Fourier transform based method which includes a realistic characterization of the sea waves. LADAR observation models are introduced and an algorithm to process those observations for yielding the relative state between the vessel and the UAV is presented, from which the UAV's state relative to an inertial frame can be obtained and used for feedback purposes. A sliding mode control algorithm is derived for tracking a landing trajectory defined by a set of desired waypoints. An extended Kalman filter (EKF) is proposed to account for process and observation noises in the design of a state estimator. The effectiveness of the control algorithm is illustrated through a simulation example.

  2. ARM - Publications: Science Team Meeting Documents

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Statistical Use of Radar-Derived Cloud Structure in Three-Dimensional Solar Radiative Transfer Calculations Evans, F., and McFarlane, S., University of Colorado, Boulder; Wiscombe, W., National Aeronautics and Space Administration-Goddard Space Flight Center Ninth Atmospheric Radiation Measurement (ARM) Science Team Meeting The Atmospheric Radiation Measurement (ARM) Millimeter-Wave Cloud Radar (MMCR) can provide valuable information about the spatial structure of clouds, which is important for

  3. Radar antenna pointing for optimized signal to noise ratio.

    SciTech Connect (OSTI)

    Doerry, Armin Walter; Marquette, Brandeis

    2013-01-01

    The Signal-to-Noise Ratio (SNR) of a radar echo signal will vary across a range swath, due to spherical wavefront spreading, atmospheric attenuation, and antenna beam illumination. The antenna beam illumination will depend on antenna pointing. Calculations of geometry are complicated by the curved earth, and atmospheric refraction. This report investigates optimizing antenna pointing to maximize the minimum SNR across the range swath.

  4. Radar echo processing with partitioned de-ramp

    DOE Patents [OSTI]

    Dubbert, Dale F.; Tise, Bertice L.

    2013-03-19

    The spurious-free dynamic range of a wideband radar system is increased by apportioning de-ramp processing across analog and digital processing domains. A chirp rate offset is applied between the received waveform and the reference waveform that is used for downconversion to the intermediate frequency (IF) range. The chirp rate offset results in a residual chirp in the IF signal prior to digitization. After digitization, the residual IF chirp is removed with digital signal processing.

  5. Texas Tech University mobile doppler radars provide unique wind

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    measurements to multi-instrument DOE Field Campaign Tech University mobile doppler radars provide unique wind measurements to multi-instrument DOE Field Campaign - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure

  6. Beam Propagator for Weather Radars, Modules 1 and 2

    Energy Science and Technology Software Center (OSTI)

    2013-10-08

    This program simulates the beam propagation of weather radar pulses under particular and realistic atmospheric conditions (without using the assumption of standard refraction conditions). It consists of two modules: radiosondings_refract_index_many.pro (MAIN MODULE) beam_propagation_function.pro(EXTERNAL FUNCTION) FOR THE MAIN MODULE, THE CODE DOES OUTPUT--INTO A FILE--THE BEAM HEIGHT AS A FUNCTION OF RANGE. THE RADIOSONDE INPUT FILES SHOULD BE ALREADY AVAILABLE BY THE USER. FOR EXAMPLE, RADIOSONDE OBSERVATION FILES CAN BE OBTAINED AT: RADIOSONDE OBSERVATIONS DOWNLOADED ATmore » "http://weather.uwyo.edu/upperair/soounding.html" OR "http://jervis.pyr.ec.gc.ca" THE EXTERNAL FUNCTION DOES THE ACTUAL COMPUTATION OF BEAM PROPAGATION. IT INCLUDES CONDITIONS OF ANOMALOUS PROPAGATION AND NEGATIVE ELEVATION ANGLES. THE EQUATIONS USED HERE WERE DERIVED BY EDWIN CAMPOS, BASED ON THE SNELL-DESCARTES LAW OF REFRACTION, CONSIDERING THE EARTH CURVATURE. THE PROGRAM REQUIRES A COMPILER FOR THE INTERACTIVE DATA LANGUAGE (IDL). DESCRIPTION AND VALIDATION DETAILS HAVE BEEN PUBLISHED IN THE PEER-REVIEWED SCIENTIFIC LITERATURE, AS FOLLOWS: Campos E. 2012. Estimating weather radar coverage over complex terrain, pp.26-32, peer reviewed, in Weather Radar and Hydrology, edited by Moore RJ, Cole SJ and Illingworth AJ. International Association of Hydrological Sciences (IAHS) Press, IAHS Publ. 351. ISBN 978-1-907161-26-1.« less

  7. HPC CLOUD APPLIED TO LATTICE OPTIMIZATION

    SciTech Connect (OSTI)

    Sun, Changchun; Nishimura, Hiroshi; James, Susan; Song, Kai; Muriki, Krishna; Qin, Yong

    2011-03-18

    As Cloud services gain in popularity for enterprise use, vendors are now turning their focus towards providing cloud services suitable for scientific computing. Recently, Amazon Elastic Compute Cloud (EC2) introduced the new Cluster Compute Instances (CCI), a new instance type specifically designed for High Performance Computing (HPC) applications. At Berkeley Lab, the physicists at the Advanced Light Source (ALS) have been running Lattice Optimization on a local cluster, but the queue wait time and the flexibility to request compute resources when needed are not ideal for rapid development work. To explore alternatives, for the first time we investigate running the Lattice Optimization application on Amazon's new CCI to demonstrate the feasibility and trade-offs of using public cloud services for science.

  8. QER- Comment of Cloud Peak Energy Inc

    Broader source: Energy.gov [DOE]

    Dear Ms Pickett Please find attached comments from Cloud Peak Energy as input to the Department of Energy’s Quadrennial Energy Review. If possible I would appreciate a confirmation that this email has been received Thank you.

  9. Building a private cloud with Open Nebula

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Short Ryan Glenn Ross Nordeen Mentors: Andree Jacobson ISTI-OFF David Kennel DCS-1 LA-UR 10-05197 Why use Virtualized Cloud Computing for HPC? * Support Legacy Software Stacks *...

  10. Evaluating the MMF Using CloudSat

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    its cloud simulations simulations Borrowed from Dave Randall, CSU The big picture The big picture ... ... . . Data ARM A-Train, MISR etc. MMF 4 km runs (CAM) Compare Run CRM...

  11. ARM - Field Campaign - Midlatitude Continental Convective Clouds...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Midlatitude Continental Convective Clouds Experiment (MC3E): Multi-Frequency...

  12. ARM - Field Campaign - Boundary Layer Cloud IOP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govCampaignsBoundary Layer Cloud IOP Campaign Links Campaign Images ARM Data Discovery Browse Data Comments? We would love to hear from you Send us a note below or call us at...

  13. ARM - Field Campaign - Arctic Cloud Infrared Imaging

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Arctic Cloud Infrared Imaging 2012.07.16 - 2014.07.31 Lead Scientist : Joseph Shaw...

  14. ARM Cloud Retrieval Ensemble Data Set (ACRED)

    SciTech Connect (OSTI)

    Zhao, C; Xie, S; Klein, SA; McCoy, R; Comstock, JM; Delanoë, J; Deng, M; Dunn, M; Hogan, RJ; Jensen, MP; Mace, GG; McFarlane, SA; O’Connor, EJ; Protat, A; Shupe, MD; Turner, D; Wang, Z

    2011-09-12

    This document describes a new Atmospheric Radiation Measurement (ARM) data set, the ARM Cloud Retrieval Ensemble Data Set (ACRED), which is created by assembling nine existing ground-based cloud retrievals of ARM measurements from different cloud retrieval algorithms. The current version of ACRED includes an hourly average of nine ground-based retrievals with vertical resolution of 45 m for 512 layers. The techniques used for the nine cloud retrievals are briefly described in this document. This document also outlines the ACRED data availability, variables, and the nine retrieval products. Technical details about the generation of ACRED, such as the methods used for time average and vertical re-grid, are also provided.

  15. ARM - Instrument - mmcr

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govInstrumentsmmcr Documentation MMCR : Handbook ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Instrument : Millimeter Wavelength Cloud Radar (MMCR) Instrument Categories Cloud Properties Picture of the Millimeter Wave Cloud Radar (MMCR) General Overview The MMCR systems probe the extent and composition of clouds at millimeter wavelengths. The MMCR is a zenith-pointing radar that operates at a frequency of 35 GHz.

  16. ARM - Publications: Science Team Meeting Documents

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Processing of ARM Millimeter Wave Cloud Radar Signals at Low Signal to Noise Conditions Kollias, P. and Albrecht B.A., University of Miami Twelfth Atmospheric Radiation Measurement (ARM) Science Team Meeting The Atmospheric Radiation Measurement (ARM) program has supported the deployment of several Millimeter Wave Cloud Radars (MMCRs) operating at 35-GHz for an accurate detection of all the hydrometeors in the atmosphere. Despite their short wavelength that increases the Rayleigh backscattering

  17. Retrievals of Cloud Fraction and Cloud Albedo from Surface-based Shortwave Radiation Measurements: A Comparison of 16 Year Measurements

    SciTech Connect (OSTI)

    Xie, Yu; Liu, Yangang; Long, Charles N.; Min, Qilong

    2014-07-27

    Ground-based radiation measurements have been widely conducted to gain information on clouds and the surface radiation budget; here several different techniques for retrieving cloud fraction (Long2006, Min2008 and XL2013) and cloud albedo (Min2008, Liu2011 and XL2013) from ground-based shortwave broadband and spectral radiation measurements are examined, and sixteen years of retrievals collected at the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site are compared. The comparison shows overall good agreement between the retrievals of both cloud fraction and cloud albedo, with noted differences however. The Long2006 and Min2008 cloud fractions are greater on average than the XL2013 values. Compared to Min2008 and Liu2011, the XL2013 retrieval of cloud albedo tends to be greater for thin clouds but smaller for thick clouds, with the differences decreasing with increasing cloud fraction. Further analysis reveals that the approaches that retrieve cloud fraction and cloud albedo separately may suffer from mutual contamination of errors in retrieved cloud fraction and cloud albedo. Potential influences of cloud absorption, land-surface albedo, cloud structure, and measurement instruments are explored.

  18. Estimation of total cloud cover from solar radiation observations at Lake Rotorua, New Zealand

    SciTech Connect (OSTI)

    Luo, Liancong; Hamilton, David; Han, Boping

    2010-03-15

    The DYRESM-CAEDYM model is a valuable tool for simulating water temperature for biochemical studies in aquatic ecosystem. The model requires inputs of surface short-wave radiation and long-wave radiation or total cloud cover fraction (TC). Long-wave radiation is often not measured directly so a method to determine TC from commonly measured short-wave solar irradiance (E{sub 0}) and theoretical short-wave solar irradiance under a clear sky (E{sub c}) has broad application. A more than 17-year (15 November 1991 to 20 February 2009) hourly solar irradiance data set was used to estimate the peak solar irradiance for each ordinal date over one year, which was assumed to be representative of solar irradiance in the absence of cloud. Comparison between these daily observed values and the modelled clear-sky solar radiation over one year was in close agreement (Pearson correlation coefficient, r = 0.995 and root mean squared error, RMSE = 12.54 W m{sup -2}). The downloaded hourly cloudiness measurements from 15 November 1991 to 20 February 2009 was used to calculate the daily values for this period and then the calculated daily values over the 17 years were used to calculate the average values for each ordinal date over one year. A regression equation between (1 - E{sub 0}/E{sub c}) and TC produced a correlation coefficient value of 0.99 (p > 0.01, n = 71). The validation of this cloud cover estimation model was conducted with observed short-wave solar radiation and TC at two sites. Values of TC derived from the model at the Lake Rotorua site gave a reasonable prediction of the observed values (RMSE = 0.10, r = 0.86, p > 0.01, n = 61). The model was also tested at Queenstown (South Island of New Zealand) and it provided satisfactory results compared to the measurements (RMSE = 0.16, r = 0.67, p > 0.01, n = 61). Therefore the model's good performance and broad applicability will contribute to the DYRESM-CAEDYM accuracy of water temperature simulation when long-wave radiation is not available. (author)

  19. Atmospheric State, Cloud Microphysics and Radiative Flux

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Mace, Gerald

    2008-01-15

    Atmospheric thermodynamics, cloud properties, radiative fluxes and radiative heating rates for the ARM Southern Great Plains (SGP) site. The data represent a characterization of the physical state of the atmospheric column compiled on a five-minute temporal and 90m vertical grid. Sources for this information include raw measurements, cloud property and radiative retrievals, retrievals and derived variables from other third-party sources, and radiative calculations using the derived quantities.

  20. Electron-Cloud Build-Up: Summary

    SciTech Connect (OSTI)

    Furman, M.A.

    2007-06-18

    I present a summary of topics relevant to the electron-cloud build-up and dissipation that were presented at the International Workshop on Electron-Cloud Effects 'ECLOUD 07' (Daegu, S. Korea, April 9-12, 2007). This summary is not meant to be a comprehensive review of the talks. Rather, I focus on those developments that I found, in my personal opinion, especially interesting. The contributions, all excellent, are posted in http://chep.knu.ac.kr/ecloud07/.

  1. Ignition of Aluminum Particles and Clouds

    SciTech Connect (OSTI)

    Kuhl, A L; Boiko, V M

    2010-04-07

    Here we review experimental data and models of the ignition of aluminum (Al) particles and clouds in explosion fields. The review considers: (i) ignition temperatures measured for single Al particles in torch experiments; (ii) thermal explosion models of the ignition of single Al particles; and (iii) the unsteady ignition Al particles clouds in reflected shock environments. These are used to develop an empirical ignition model appropriate for numerical simulations of Al particle combustion in shock dispersed fuel explosions.

  2. Posters Sensitivity of Cirrus Cloud Radiative

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    7 Posters Sensitivity of Cirrus Cloud Radiative Properties to Ice Crystal Size and Shape in General Circulation Model Simulations D. L. Mitchell Desert Research Institute Reno, Nevada J. E. Kristjánsson Department of Geophysics University of Oslo, Norway M. J. Newman Los Alamos National Laboratory Los Alamos, New Mexico Introduction Recent research (e.g., Mitchell and Arnott 1994) has shown that the radiative properties of cirrus clouds (i.e., optical depth, albedo, emissivity) depend on the

  3. ARM Cloud Properties Working Group: Meeting Logistics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cloud Properties WG Breakout Session 2008 ARM Science Team Meeting Mar. 10, 2008, Norfolk, VA Monday March 10, 2008 1500 to 1515: R. Hogan - A Proposal for ARM support of Cloudnet Activities 1515 to 1530: M. Jensen - Cloud Properties Value- Added Product Development 1530 to 1545: C. Long - Instrument Group Report 1545 to 1600: S. Matrosov - WSR-88D data for ARM science 1600 to 1615: Y. Zhao - A BimodalParticle Distribution Assumption in Cirrus: Comparison of retrieval results with in situ

  4. Atmospheric State, Cloud Microphysics and Radiative Flux

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Mace, Gerald

    Atmospheric thermodynamics, cloud properties, radiative fluxes and radiative heating rates for the ARM Southern Great Plains (SGP) site. The data represent a characterization of the physical state of the atmospheric column compiled on a five-minute temporal and 90m vertical grid. Sources for this information include raw measurements, cloud property and radiative retrievals, retrievals and derived variables from other third-party sources, and radiative calculations using the derived quantities.

  5. ARM - Publications: Science Team Meeting Documents: Day and Night cloud

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    fraction - Cloud Inter-Compariosn IOP results Day and Night cloud fraction - Cloud Inter-Compariosn IOP results Genkova, Iliana University of Illinois-Champaign Long, Chuck Pacific Northwest National Laboratory Turner, David Pacific Northwest National Laboratory We present results from the CIC IOP from March-may, 2003. Day time and night time cloud fraction retrieval algorithms have been presented and intercompared. Amount of low, middle and high cloud have been estimated and compared to

  6. Icy Cirrus Clouds to Be Studied This Spring

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Icy Cirrus Clouds to Be Studied This Spring Mid-latitude cirrus clouds, which are composed solely of ice crystals, will be the focus of an intensive operational period (IOP) in April and May 2004 at the ARM Climate Research Facility (ACRF) SGP site. Researchers will be probing the clouds with aircraft-based instruments to gather detailed information about the clouds' physical characteristics. To make measurements in cirrus clouds, which generally form in the atmosphere at and above 20,000 feet

  7. Star formation relations in nearby molecular clouds

    SciTech Connect (OSTI)

    Evans, Neal J. II; Heiderman, Amanda; Vutisalchavakul, Nalin

    2014-02-20

    We test some ideas for star formation relations against data on local molecular clouds. On a cloud by cloud basis, the relation between the surface density of star formation rate and surface density of gas divided by a free-fall time, calculated from the mean cloud density, shows no significant correlation. If a crossing time is substituted for the free-fall time, there is even less correlation. Within a cloud, the star formation rate volume and surface densities increase rapidly with the corresponding gas densities, faster than predicted by models using the free-fall time defined from the local density. A model in which the star formation rate depends linearly on the mass of gas above a visual extinction of 8 mag describes the data on these clouds, with very low dispersion. The data on regions of very massive star formation, with improved star formation rates based on free-free emission from ionized gas, also agree with this linear relation.

  8. Improving ISR Radar Utilization (How I quit blaming the user and made the radar easier to use).

    SciTech Connect (OSTI)

    Doerry, Armin W.

    2014-08-01

    In modern multi - sensor multi - mode Intelligence, Surveillance, and Reconnaissance ( ISR ) platforms, the plethora of options available to a sensor/payload operator are quite large, leading to an over - worked operator often down - selecting to favorite sensors an d modes. For example, Full Motion Video (FMV) is justifiably a favorite sensor at the expense of radar modes, even if radar modes can offer unique and advantageous information. The challenge is then to increase the utilization of the radar modes in a man ner attractive to the sensor/payload operator. We propose that this is best accomplished by combining sensor modes and displays into 'super - modes'. - 4 - Acknowledgements This report is the result of a n unfunded research and development activity . Sandia Natio nal Laboratories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL850 00.

  9. Month-Long 2D Cloud-Resolving Model Simulation and Resultant Statistics of Cloud Systems Over the ARM SGP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Month-Long 2D Cloud-Resolving Model Simulation and Resultant Statistics of Cloud Systems Over the ARM SGP X. Wu Department of Geological and Atmospheric Sciences Iowa State University Ames, Iowa X.-Z. Liang Illinois State Water Survey University of Illinois Urbana-Champaign, Illinois Introduction The cloud-resolving model (CRM) has recently emerged as a useful tool to develop improved representations of convections, clouds, and cloud-radiation interactions in general circulation models (GCMs).

  10. ARM - VAP Process - kazrarscl

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    are those considered scientifically relevant. Cloud base height Cloud top height Radar Doppler Radar polarization Radar reflectivity Vertical velocity Locations North Slope...

  11. Slide 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    clouds are removed with single-layer clouds. Case: Consistent with radar observation Case: Consistent with radar observation Case: Consistent with radar observation...

  12. Posters Climate Zones for Maritime Clouds A. B. White and D....

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    power (15-m resolution) is analyzed to detect cloud layers using a specified cloud detection limit. In addition to measurements of cloud base, the ceilometer can also provide...

  13. The role of precipitation size distributions in km-scale NWP simulations of intense precipitation: Evaluation of cloud properties and surface precipitation

    SciTech Connect (OSTI)

    VanWeverberg K.; Vogelmann A.; vanLipzig, N. P. M.; Delobbec, L.

    2012-04-01

    We investigate the sensitivity of simulated cloud properties and surface precipitation to assumptions regarding the size distributions of the precipitating hydrometeors in a one-moment bulk microphysics scheme. Three sensitivity experiments were applied to two composites of 15 convective and 15 frontal stratiform intense precipitation events observed in a coastal midlatitude region (Belgium), which were evaluated against satellite-retrieved cloud properties and radar-rain-gauge derived surface precipitation. It is found that the cloud optical thickness distribution was well captured by all experiments, although a significant underestimation of cloudiness occurred in the convective composite. The cloud-top-pressure distribution was improved most by more realistic snow size distributions (including a temperature-dependent intercept parameter and non-spherical snow for the calculation of the slope parameter), due to increased snow depositional growth at high altitudes. Surface precipitation was far less sensitive to whether graupel or hail was chosen as the rimed ice species, as compared to previous idealized experiments. This smaller difference in sensitivity could be explained by the stronger updraught velocities and higher freezing levels in the idealized experiments compared to typical coastal midlatitude environmental conditions.

  14. Evaluation of convection-permitting model simulations of cloud populations associated with the Madden-Julian Oscillation using data collected during the AMIE/DYNAMO field campaign

    SciTech Connect (OSTI)

    Hagos, Samson M.; Feng, Zhe; Burleyson, Casey D.; Lim, Kyo-Sun; Long, Charles N.; Wu, Di; Thompson, Gregory

    2014-11-12

    Regional cloud permitting model simulations of cloud populations observed during the 2011 ARM Madden Julian Oscillation Investigation Experiment/ Dynamics of Madden-Julian Experiment (AMIE/DYNAMO) field campaign are evaluated against radar and ship-based measurements. Sensitivity of model simulated surface rain rate statistics to parameters and parameterization of hydrometeor sizes in five commonly used WRF microphysics schemes are examined. It is shown that at 2 km grid spacing, the model generally overestimates rain rate from large and deep convective cores. Sensitivity runs involving variation of parameters that affect rain drop or ice particle size distribution (more aggressive break-up process etc) generally reduce the bias in rain-rate and boundary layer temperature statistics as the smaller particles become more vulnerable to evaporation. Furthermore significant improvement in the convective rain-rate statistics is observed when the horizontal grid-spacing is reduced to 1 km and 0.5 km, while it is worsened when run at 4 km grid spacing as increased turbulence enhances evaporation. The results suggest modulation of evaporation processes, through parameterization of turbulent mixing and break-up of hydrometeors may provide a potential avenue for correcting cloud statistics and associated boundary layer temperature biases in regional and global cloud permitting model simulations.

  15. Wave-wave interactions in solar type III radio bursts

    SciTech Connect (OSTI)

    Thejappa, G.; MacDowall, R. J.

    2014-02-11

    The high time resolution observations from the STEREO/WAVES experiment show that in type III radio bursts, the Langmuir waves often occur as localized magnetic field aligned coherent wave packets with durations of a few ms and with peak intensities well exceeding the strong turbulence thresholds. Some of these wave packets show spectral signatures of beam-resonant Langmuir waves, down- and up-shifted sidebands, and ion sound waves, with frequencies, wave numbers, and tricoherences satisfying the resonance conditions of the oscillating two stream instability (four wave interaction). The spectra of a few of these wave packets also contain peaks at f{sub pe}, 2f{sub pe} and 3 f{sub pe} (f{sub pe} is the electron plasma frequency), with frequencies, wave numbers and bicoherences (computed using the wavelet based bispectral analysis techniques) satisfying the resonance conditions of three wave interactions: (1) excitation of second harmonic electromagnetic waves as a result of coalescence of two oppositely propagating Langmuir waves, and (2) excitation of third harmonic electromagnetic waves as a result of coalescence of Langmuir waves with second harmonic electromagnetic waves. The implication of these findings is that the strong turbulence processes play major roles in beam stabilization as well as conversion of Langmuir waves into escaping radiation in type III radio bursts.

  16. HIGH-RESOLUTION OBSERVATIONS AND THE PHYSICS OF HIGH-VELOCITY CLOUD A0

    SciTech Connect (OSTI)

    Verschuur, Gerrit L.

    2013-04-01

    The neutral hydrogen structure of high-velocity cloud A0 (at about -180 km s{sup -1}) has been mapped with a 9.'1 resolution. Gaussian decomposition of the profiles is used to separately map families of components defined by similarities in center velocities and line widths. About 70% of the H I gas is in the form of a narrow, twisted filament whose typical line widths are of the order of 24 km s{sup -1}. Many bright features with narrow line widths of the order of 6 km s{sup -1}, clouds, are located in and near the filament. A third category with properties between those of the filament and clouds appears in the data. The clouds are not always co-located with the broader line width filament emission as seen projected on the sky. Under the assumption that magnetic fields underlie the presence of the filament, a theorem is developed for its stability in terms of a toroidal magnetic field generated by the flow of gas along field lines. It is suggested that the axial magnetic field strength may be derived from the excess line width of the H I emission over and above that due to kinetic temperature by invoking the role of Alfven waves that create what is in essence a form of magnetic turbulence. At a distance of 200 pc the axial and the derived toroidal magnetic field strengths in the filament are then about 6 {mu}G while for the clouds they are about 4 {mu}G. The dependence of the derived field strength on distance is discussed.

  17. Lattice Waves, Spin Waves, and Neutron Scattering

    DOE R&D Accomplishments [OSTI]

    Brockhouse, Bertram N.

    1962-03-01

    Use of neutron inelastic scattering to study the forces between atoms in solids is treated. One-phonon processes and lattice vibrations are discussed, and experiments that verified the existence of the quantum of lattice vibrations, the phonon, are reviewed. Dispersion curves, phonon frequencies and absorption, and models for dispersion calculations are discussed. Experiments on the crystal dynamics of metals are examined. Dispersion curves are presented and analyzed; theory of lattice dynamics is considered; effects of Fermi surfaces on dispersion curves; electron-phonon interactions, electronic structure influence on lattice vibrations, and phonon lifetimes are explored. The dispersion relation of spin waves in crystals and experiments in which dispersion curves for spin waves in Co-Fe alloy and magnons in magnetite were obtained and the reality of the magnon was demonstrated are discussed. (D.C.W)

  18. Apodized RFI filtering of synthetic aperture radar images

    SciTech Connect (OSTI)

    Doerry, Armin Walter

    2014-02-01

    Fine resolution Synthetic Aperture Radar (SAR) systems necessarily require wide bandwidths that often overlap spectrum utilized by other wireless services. These other emitters pose a source of Radio Frequency Interference (RFI) to the SAR echo signals that degrades SAR image quality. Filtering, or excising, the offending spectral contaminants will mitigate the interference, but at a cost of often degrading the SAR image in other ways, notably by raising offensive sidelobe levels. This report proposes borrowing an idea from nonlinear sidelobe apodization techniques to suppress interference without the attendant increase in sidelobe levels. The simple post-processing technique is termed Apodized RFI Filtering (ARF).

  19. Synthetic aperture radar images with composite azimuth resolution

    DOE Patents [OSTI]

    Bielek, Timothy P; Bickel, Douglas L

    2015-03-31

    A synthetic aperture radar (SAR) image is produced by using all phase histories of a set of phase histories to produce a first pixel array having a first azimuth resolution, and using less than all phase histories of the set to produce a second pixel array having a second azimuth resolution that is coarser than the first azimuth resolution. The first and second pixel arrays are combined to produce a third pixel array defining a desired SAR image that shows distinct shadows of moving objects while preserving detail in stationary background clutter.

  20. I. I. Rabi, Nuclear Magnetic Resonance (NMR), and Radar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    I. I. Rabi, Nuclear Magnetic Resonance (NMR), and Radar Resources with Additional Information I.I. Rabi Courtesy of Brookhaven National Laboratory 'Isidor Isaac Rabi [was] a pioneer in exploring the atom and a major force in 20th-century physics.'1 He won the 1944 Nobel Prize in Physics "for his resonance method for recording the magnetic properties of atomic nuclei". 'His work in turn made possible the precise measurements necessary for the development of the atomic clock, the laser

  1. Traveling-wave photodetector

    DOE Patents [OSTI]

    Hietala, Vincent M. (Placitas, NM); Vawter, Gregory A. (Albuquerque, NM)

    1993-01-01

    The traveling-wave photodetector of the present invention combines an absorptive optical waveguide and an electrical transmission line, in which optical absorption in the waveguide results in a photocurrent at the electrodes of the electrical transmission line. The optical waveguide and electrical transmission line of the electrically distributed traveling-wave photodetector are designed to achieve matched velocities between the light in the optical waveguide and electrical signal generated on the transmission line. This velocity synchronization provides the traveling-wave photodetector with a large electrical bandwidth and a high quantum efficiency, because of the effective extended volume for optical absorption. The traveling-wave photodetector also provides large power dissipation, because of its large physical size.

  2. Traveling-wave photodetector

    DOE Patents [OSTI]

    Hietala, V.M.; Vawter, G.A.

    1993-12-14

    The traveling-wave photodetector of the present invention combines an absorptive optical waveguide and an electrical transmission line, in which optical absorption in the waveguide results in a photocurrent at the electrodes of the electrical transmission line. The optical waveguide and electrical transmission line of the electrically distributed traveling-wave photodetector are designed to achieve matched velocities between the light in the optical waveguide and electrical signal generated on the transmission line. This velocity synchronization provides the traveling-wave photodetector with a large electrical bandwidth and a high quantum efficiency, because of the effective extended volume for optical absorption. The traveling-wave photodetector also provides large power dissipation, because of its large physical size. 4 figures.

  3. WindWaveFloat

    SciTech Connect (OSTI)

    Weinstein, Alla

    2011-11-01

    Presentation from the 2011 Water Peer Review includes in which principal investigator Alla Weinstein discusses project progress in development of a floating offshore wind structure - the WindFloat - and incorporation therin of a Spherical Wave Energy Device.

  4. Magellan: experiences from a Science Cloud

    SciTech Connect (OSTI)

    Ramakrishnan, Lavanya; Zbiegel, Piotr; Campbell, Scott; Bradshaw, Rick; Canon, Richard; Coghlan, Susan; Sakrejda, Iwona; Desai, Narayan; Declerck, Tina; Liu, Anping

    2011-02-02

    Cloud resources promise to be an avenue to address new categories of scientific applications including data-intensive science applications, on-demand/surge computing, and applications that require customized software environments. However, there is a limited understanding on how to operate and use clouds for scientific applications. Magellan, a project funded through the Department of Energy?s (DOE) Advanced Scientific Computing Research (ASCR) program, is investigating the use of cloud computing for science at the Argonne Leadership Computing Facility (ALCF) and the National Energy Research Scientific Computing Facility (NERSC). In this paper, we detail the experiences to date at both sites and identify the gaps and open challenges from both a resource provider as well as application perspective.

  5. Wave Propagation Program

    Energy Science and Technology Software Center (OSTI)

    2007-01-08

    WPP is a massively parallel, 3D, C++, finite-difference elastodynamic wave propagation code. Typical applications for wave propagation with WPP include: evaluation of seismic event scenarios and damage from earthquakes, non-destructive evaluation of materials, underground facility detection, oil and gas exploration, predicting the electro-magnetic fields in accelerators, and acoustic noise generation. For more information, see User’s Manual [1].

  6. Cloud-based Architecture Capabilities Summary Report

    SciTech Connect (OSTI)

    Vang, Leng; Prescott, Steven R; Smith, Curtis

    2014-09-01

    In collaborating scientific research arena it is important to have an environment where analysts have access to a shared of information documents, software tools and be able to accurately maintain and track historical changes in models. A new cloud-based environment would be accessible remotely from anywhere regardless of computing platforms given that the platform has available of Internet access and proper browser capabilities. Information stored at this environment would be restricted based on user assigned credentials. This report reviews development of a Cloud-based Architecture Capabilities (CAC) as a web portal for PRA tools.

  7. ARM - Field Campaign - Thin Cloud Rotating Shadowband Radiometer

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Thin Cloud Rotating Shadowband Radiometer 2008.01.08 - 2008.07.18 Lead Scientist : Mary Jane Bartholomew For data sets, see below. Abstract The Thin-Cloud Rotating Shadowband...

  8. E-Cloud Build-up in Grooved Chambers

    SciTech Connect (OSTI)

    Venturini, Marco

    2007-05-01

    We simulate electron cloud build-up in a grooved vacuumchamber including the effect of space charge from the electrons. Weidentify conditions for e-cloud suppression and make contact withprevious estimates of an effective secondary electron yield for groovedsurfaces.

  9. Treatments of Inhomogeneous Clouds in a GCM Column Radiation...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of fractal stratocumulus clouds. J. Atmos. Sci., 51, 2434 -2455. Chou, M.-D., M. J. Suarez, C.-H. Ho, M. M.-H. Yan, and K.-T. Lee, 1998: Parameterizations for cloud...

  10. Simulation of E-Cloud Driven Instability And Its Attenuation...

    Office of Scientific and Technical Information (OSTI)

    of E-Cloud Driven Instability And Its Attenuation Using a Feedback System in the CERN SPS Citation Details In-Document Search Title: Simulation of E-Cloud Driven Instability...

  11. Observations of the Madden Julian Oscillation for Cloud Modeling...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Dyn.) Manus MJO signal in downwelling SW cloud radiative forcing GRL paper submitted Y. Wang, C. Long, and J. Mather Manus MJO signal in retrieved cloud amount GRL paper...

  12. Radiosonde observations at Pt. Reyes and cloud properties retrieved...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Radiosonde observations at Pt. Reyes and cloud properties retrieved from GOES-WEST Inoue, Toshiro MRIJMA Category: Field Campaigns Low-level cloud formed off the west coast of...

  13. ARM - Field Campaign - Marine ARM GPCI Investigations of Clouds...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Marine ARM GPCI Investigations of Clouds (MAGIC): Cloud Properties from Zenith...

  14. ARM - Field Campaign - Biogenic Aerosols - Effects on Clouds...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Climate Campaign Links BAECC Website ARM Data Discovery Browse Data Related Campaigns Biogenic Aerosols - Effects on Clouds and Climate: Cloud OD Sensor TWST 2014.06.15, Scott, AMF...

  15. A TWP-ICE High-Level Cloud Case Study

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A TWP-ICE High-Level Cloud Case Study Mace, Gerald University of Utah Category: Field Campaigns The Tropical Warm Pool International Cloud Experiment (TWP ICE) was conducted near...

  16. Microsoft Word - Group3Cloud Properties(RS).docx

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... for (a) column clouds and (b) circle clouds. 2.0 References Clothiaux, EE, TP Ackerman, GG Mace, KP Moran, RT Marchand, MA Miller, and BE Martner. 2000. "Objective determination ...

  17. Intercomparison of model simulations of mixed-phase clouds observed during

    Office of Scientific and Technical Information (OSTI)

    the ARM Mixed-Phase Arctic Cloud Experiment. I: Single layer cloud (Journal Article) | SciTech Connect Journal Article: Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. I: Single layer cloud Citation Details In-Document Search Title: Intercomparison of model simulations of mixed-phase clouds observed during the ARM Mixed-Phase Arctic Cloud Experiment. I: Single layer cloud Results are presented from an intercomparison of

  18. The dependence of cloud particle size and precipitation probability...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    effect Hongfei Shao and Guosheng Liu Meteorology Department, Florida State University INTRODUCTION INTRODUCTION Anthropogenic aerosols enhance cloud reflectance of solar...

  19. ARM - Publications: Science Team Meeting Documents: Cloud Radiative Forcing

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    at the ARM Climate Research Facility: Part 2. The Vertical Redistribution of Radiant Energy by Clouds. Cloud Radiative Forcing at the ARM Climate Research Facility: Part 2. The Vertical Redistribution of Radiant Energy by Clouds. Mace, Gerald University of Utah Benson, Sally University of Utah Kato, Seiji Hampton University/NASA Langley Research Center Documentation with data of the effects of clouds on the radiant energy balance of the surface and atmosphere represent a critical shortcoming

  20. Direct Numerical Simulations and Robust Predictions of Cloud Cavitation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Collapse | Argonne Leadership Computing Facility Initiation of cloud cavitation collapse for 50,000 bubbles Initiation of cloud cavitation collapse for 50,000 bubbles. Jonas Sukys, ETH Zurich Direct Numerical Simulations and Robust Predictions of Cloud Cavitation Collapse PI Name: Petros Koumoutsakos PI Email: petros@ethz.ch Institution: ETH Zurich Allocation Program: INCITE Allocation Hours at ALCF: 72 Million Year: 2016 Research Domain: Engineering Cloud cavitation collapse-the evolution

  1. ARM - PI Product - Tropical Cloud Properties and Radiative Heating Profiles

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ProductsTropical Cloud Properties and Radiative Heating Profiles ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Tropical Cloud Properties and Radiative Heating Profiles We have generated a suite of products that includes merged soundings, cloud microphysics, and radiative fluxes and heating profiles. The cloud microphysics is strongly based on the ARM Microbase value added product (Miller et al.,

  2. Limiting Factors for Convective Cloud Top Height in the Tropics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Limiting Factors for Convective Cloud Top Height in the Tropics M. P. Jensen and A. D. Del Genio National Aeronautics and Space Administration Goddard Institute for Space Studies Columbia University New York, New York Introduction Populations of tropical convective clouds are mainly comprised of three types: shallow trade cumulus, mid-level cumulus congestus and deep convective clouds (Johnson et al. 1999). Each of these cloud types has different impacts on the local radiation and water budgets.

  3. LES Modeling of High Resolution Satellite Cloud Spatial and Thermal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Structure at ARM-SGP site: How well can we Simulate Clouds from Space? LES Modeling of High Resolution Satellite Cloud Spatial and Thermal Structure at ARM-SGP site: How well can we Simulate Clouds from Space? Dubey, Manvendra DOE/Los Alamos National Laboratory Chylek, Petr DOE/Los Alamos National Laboratory Reisner, Jon Los Alamos National Laboratory Porch, William Los Alamos National Laboratory Category: Cloud Properties We report high fidelity observations of the spatial and thermal

  4. To the Cloud! Apidae Helps Modelers Turn Information into Knowledge |

    Energy Savers [EERE]

    Department of Energy To the Cloud! Apidae Helps Modelers Turn Information into Knowledge To the Cloud! Apidae Helps Modelers Turn Information into Knowledge October 26, 2015 - 2:41pm Addthis Apidae is a collection of cloud-based simulation and data analysis tools that help modelers better understand their models. Image credit: BUILDlab. Apidae is a collection of cloud-based simulation and data analysis tools that help modelers better understand their models. Image credit: BUILDlab. Apidae

  5. Cloud Property Retrieval Products for Graciosa Island, Azores

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Dong, Xiquan

    2014-05-05

    The motivation for developing this product was to use the Dong et al. 1998 method to retrieve cloud microphysical properties, such as cloud droplet effective radius, cloud droplets number concentration, and optical thickness. These retrieved properties have been used to validate the satellite retrieval, and evaluate the climate simulations and reanalyses. We had been using this method to retrieve cloud microphysical properties over ARM SGP and NSA sites. We also modified the method for the AMF at Shouxian, China and some IOPs, e.g. ARM IOP at SGP in March, 2000. The ARSCL data from ARM data archive over the SGP and NSA have been used to determine the cloud boundary and cloud phase. For these ARM permanent sites, the ARSCL data was developed based on MMCR measurements, however, there were no data available at the Azores field campaign. We followed the steps to generate this derived product and also include the MPLCMASK cloud retrievals to determine the most accurate cloud boundaries, including the thin cirrus clouds that WACR may under-detect. We use these as input to retrieve the cloud microphysical properties. Due to the different temporal resolutions of the derived cloud boundary heights product and the cloud properties product, we submit them as two separate netcdf files.

  6. Cloud Property Retrieval Products for Graciosa Island, Azores

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Dong, Xiquan

    The motivation for developing this product was to use the Dong et al. 1998 method to retrieve cloud microphysical properties, such as cloud droplet effective radius, cloud droplets number concentration, and optical thickness. These retrieved properties have been used to validate the satellite retrieval, and evaluate the climate simulations and reanalyses. We had been using this method to retrieve cloud microphysical properties over ARM SGP and NSA sites. We also modified the method for the AMF at Shouxian, China and some IOPs, e.g. ARM IOP at SGP in March, 2000. The ARSCL data from ARM data archive over the SGP and NSA have been used to determine the cloud boundary and cloud phase. For these ARM permanent sites, the ARSCL data was developed based on MMCR measurements, however, there were no data available at the Azores field campaign. We followed the steps to generate this derived product and also include the MPLCMASK cloud retrievals to determine the most accurate cloud boundaries, including the thin cirrus clouds that WACR may under-detect. We use these as input to retrieve the cloud microphysical properties. Due to the different temporal resolutions of the derived cloud boundary heights product and the cloud properties product, we submit them as two separate netcdf files.

  7. Argonne's Magellan Cloud Computing Research Project

    ScienceCinema (OSTI)

    Beckman, Pete

    2013-04-19

    Pete Beckman, head of Argonne's Leadership Computing Facility (ALCF), discusses the Department of Energy's new $32-million Magellan project, which designed to test how cloud computing can be used for scientific research. More information: http://www.anl.gov/Media_Center/News/2009/news091014a.html

  8. The Tropical Warm Pool International Cloud Experiment

    SciTech Connect (OSTI)

    May, Peter T.; Mather, James H.; Vaughan, Geraint; Jakob, Christian; McFarquhar, Greg; Bower, Keith; Mace, Gerald G.

    2008-05-01

    One of the most complete data sets describing tropical convection ever collected will result from the upcoming Tropical Warm Pool International Cloud Experiment (TWP-ICE) in the area around Darwin, Northern Australia in January and February 2006. The aims of the experiment, which will be operated in conjunction with the DOE Atmospheric Radiation Measurement (ARM) site in Darwin, will be to examine convective cloud systems from their initial stages through to the decay of the cirrus generated and to measure their impact on the environment. The experiment will include an unprecedented network of ground-based observations (soundings, active and passive remote sensors) combined with low, mid and high altitude aircraft for in-situ and remote sensing measurements. A crucial outcome of the experiment will be a data set suitable to provide the forcing and evaluation data required by cloud resolving and single column models as well as global climate models (GCMs) with the aim to contribute to parameterization development. This data set will provide the necessary link between the observed cloud properties and the models that are attempting to simulate them. The experiment is a large multi-agency experiment including substantial contributions from the United States DOE ARM program, ARM-UAV program, NASA, the Australian Bureau of Meteorology, CSIRO, EU programs and many universities.

  9. Detecting and Evaluating the Effect of Overlaying Thin Cirrus Cloud on MODIS Retrieved Water-Cloud Droplet Effective Radius

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Detecting and Evaluating the Effect of Overlaying Thin Cirrus Cloud on MODIS Retrieved Water-Cloud Droplet Effective Radius F.-L Chang and Z. Li Earth System Science Interdisciplinary Center University of Maryland College Park, Maryland Z. Li Department of Meteorology University of Maryland College Park, Maryland Introduction Cirrus clouds can largely modify the solar reflected and terrestrial emitted radiances. The ubiquitous presence of cirrus clouds has a global coverage of about 20% to30%

  10. Infrared Cloud Imager Measurements of Cloud Statistics from the 2003 Cloudiness Intercomparison Campaign

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Infrared Cloud Imager Measurements of Cloud Statistics from the 2003 Cloudiness Intercomparison Campaign B. Thurairajah and J. A. Shaw Department of Electrical and Computer Engineering Montana State University Bozeman, Montana Introduction The Cloudiness Inter-Comparison Intensive Operational Period (CIC IOP) occurred at the Atmospheric Radiation Measurement (ARM), Southern Great Plains (SGP) central facility site in Lamont, Oklahoma from mid-February to mid-April 2003 (Kassianov et al. 2004).

  11. Water clouds in Y dwarfs and exoplanets

    SciTech Connect (OSTI)

    Morley, Caroline V.; Fortney, Jonathan J.; Marley, Mark S.; Lupu, Roxana; Greene, Tom; Saumon, Didier; Lodders, Katharina

    2014-05-20

    The formation of clouds affects brown dwarf and planetary atmospheres of nearly all effective temperatures. Iron and silicate condense in L dwarf atmospheres and dissipate at the L/T transition. Minor species such as sulfides and salts condense in mid- to late T dwarfs. For brown dwarfs below T {sub eff} ? 450 K, water condenses in the upper atmosphere to form ice clouds. Currently, over a dozen objects in this temperature range have been discovered, and few previous theoretical studies have addressed the effect of water clouds on brown dwarf or exoplanetary spectra. Here we present a new grid of models that include the effect of water cloud opacity. We find that they become optically thick in objects below T {sub eff} ? 350-375 K. Unlike refractory cloud materials, water-ice particles are significantly nongray absorbers; they predominantly scatter at optical wavelengths through the J band and absorb in the infrared with prominent features, the strongest of which is at 2.8 ?m. H{sub 2}O, NH{sub 3}, CH{sub 4}, and H{sub 2} CIA are dominant opacity sources; less abundant species may also be detectable, including the alkalis, H{sub 2}S, and PH{sub 3}. PH{sub 3}, which has been detected in Jupiter, is expected to have a strong signature in the mid-infrared at 4.3 ?m in Y dwarfs around T {sub eff} = 450 K; if disequilibrium chemistry increases the abundance of PH{sub 3}, it may be detectable over a wider effective temperature range than models predict. We show results incorporating disequilibrium nitrogen and carbon chemistry and predict signatures of low gravity in planetary mass objects. Finally, we make predictions for the observability of Y dwarfs and planets with existing and future instruments, including the James Webb Space Telescope and Gemini Planet Imager.

  12. Piezoelectric wave motor

    DOE Patents [OSTI]

    Yerganian, Simon Scott

    2003-02-11

    A piezoelectric motor having a stator in which piezoelectric elements are contained in slots formed in the stator transverse to the desired wave motion. When an electric field is imposed on the elements, deformation of the elements imposes a force perpendicular to the sides of the slot, deforming the stator. Appropriate frequency and phase-shifting of the electric field will produce a wave in the stator and motion in a rotor. In a preferred aspect, the piezoelectric elements are configured so that deformation of the elements in the direction of an imposed electric field, generally referred to as the d.sub.33 direction, is utilized to produce wave motion in the stator. In a further aspect, the elements are compressed into the slots so as to minimize tensile stresses on the elements in use.

  13. Piezoelectric wave motor

    DOE Patents [OSTI]

    Yerganian, Simon Scott

    2001-07-17

    A piezoelectric motor having a stator in which piezoelectric elements are contained in slots formed in the stator transverse to the desired wave motion. When an electric field is imposed on the elements, deformation of the elements imposes a force perpendicular to the sides of the slot, deforming the stator. Appropriate frequency and phase shifting of the electric field will produce a wave in the stator and motion in a rotor. In a preferred aspect, the piezoelectric elements are configured so that deformation of the elements in direction of an imposed electric field, generally referred to as the d.sub.33 direction, is utilized to produce wave motion in the stator. In a further aspect, the elements are compressed into the slots so as to minimize tensile stresses on the elements in use.

  14. Standing wave compressor

    DOE Patents [OSTI]

    Lucas, Timothy S. (4614 River Mill Ct., Glen Allen, VA 23060)

    1991-01-01

    A compressor for compression-evaporation cooling systems, which requires no moving parts. A gaseous refrigerant inside a chamber is acoustically compressed and conveyed by means of a standing acoustic wave which is set up in the gaseous refrigerant. This standing acoustic wave can be driven either by a transducer, or by direct exposure of the gas to microwave and infrared sources, including solar energy. Input and output ports arranged along the chamber provide for the intake and discharge of the gaseous refrigerant. These ports can be provided with optional valve arrangements, so as to increase the compressor's pressure differential. The performance of the compressor in either of its transducer or electromagnetically driven configurations, can be optimized by a controlling circuit. This controlling circuit holds the wavelength of the standing acoustical wave constant, by changing the driving frequency in response to varying operating conditions.

  15. Adaptive multiconfigurational wave functions

    SciTech Connect (OSTI)

    Evangelista, Francesco A.

    2014-03-28

    A method is suggested to build simple multiconfigurational wave functions specified uniquely by an energy cutoff ?. These are constructed from a model space containing determinants with energy relative to that of the most stable determinant no greater than ?. The resulting ?-CI wave function is adaptive, being able to represent both single-reference and multireference electronic states. We also consider a more compact wave function parameterization (?+SD-CI), which is based on a small ?-CI reference and adds a selection of all the singly and doubly excited determinants generated from it. We report two heuristic algorithms to build ?-CI wave functions. The first is based on an approximate prescreening of the full configuration interaction space, while the second performs a breadth-first search coupled with pruning. The ?-CI and ?+SD-CI approaches are used to compute the dissociation curve of N{sub 2} and the potential energy curves for the first three singlet states of C{sub 2}. Special attention is paid to the issue of energy discontinuities caused by changes in the size of the ?-CI wave function along the potential energy curve. This problem is shown to be solvable by smoothing the matrix elements of the Hamiltonian. Our last example, involving the Cu{sub 2}O{sub 2}{sup 2+} core, illustrates an alternative use of the ?-CI method: as a tool to both estimate the multireference character of a wave function and to create a compact model space to be used in subsequent high-level multireference coupled cluster computations.

  16. ARM - Evaluation Product - ARM Cloud Retrieval Ensemble Data

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ProductsARM Cloud Retrieval Ensemble Data ARM Data Discovery Browse Data Documentation Use the Data File Inventory tool to view data availability at the file level. Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Evaluation Product : ARM Cloud Retrieval Ensemble Data The ARM Cloud Retrieval Ensemble Data (ACRED) set is a multi-year cloud microphysical property ensemble data set created by assembling existing ARM cloud retrievals, which are based

  17. ARM - PI Product - Cloud Property Retrieval Products for Graciosa Island,

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Azores ProductsCloud Property Retrieval Products for Graciosa Island, Azores ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Cloud Property Retrieval Products for Graciosa Island, Azores [ research data - ASR funded ] The motivation for developing this product was to use the Dong et al. 1998 method to retrieve cloud microphysical properties, such as cloud droplet effective radius, cloud droplets

  18. Explosive plane-wave lens

    DOE Patents [OSTI]

    Marsh, Stanley P. (Los Alamos, NM)

    1988-01-01

    An explosive plane-wave air lens which enables a spherical wave form to be converted to a planar wave without the need to specially machine or shape explosive materials is described. A disc-shaped impactor having a greater thickness at its center than around its periphery is used to convert the spherical wave into a plane wave. When the wave reaches the impactor, the center of the impactor moves first because the spherical wave reaches the center of the impactor first. The wave strikes the impactor later in time as one moves radially along the impactor. Because the impactor is thinner as one moves radially outward, the velocity of the impactor is greater at the periphery than at the center. An acceptor explosive is positioned so that the impactor strikes the acceptor simultaneously. Consequently, a plane detonation wave is propagated through the acceptor explosive.

  19. Explosive plane-wave lens

    DOE Patents [OSTI]

    Marsh, S.P.

    1988-03-08

    An explosive plane-wave air lens which enables a spherical wave form to be converted to a planar wave without the need to specially machine or shape explosive materials is described. A disc-shaped impactor having a greater thickness at its center than around its periphery is used to convert the spherical wave into a plane wave. When the wave reaches the impactor, the center of the impactor moves first because the spherical wave reaches the center of the impactor first. The wave strikes the impactor later in time as one moves radially along the impactor. Because the impactor is thinner as one moves radially outward, the velocity of the impactor is greater at the periphery than at the center. An acceptor explosive is positioned so that the impactor strikes the acceptor simultaneously. Consequently, a plane detonation wave is propagated through the acceptor explosive. 4 figs.

  20. Explosive plane-wave lens

    DOE Patents [OSTI]

    Marsh, S.P.

    1987-03-12

    An explosive plane-wave air lens which enables a spherical wave form to be converted to a planar wave without the need to specially machine or shape explosive materials is described. A disc-shaped impactor having a greater thickness at its center than around its periphery is used to convert the spherical wave into a plane wave. When the wave reaches the impactor, the center of the impactor moves first because the spherical wave reaches the center of the impactor first. The wave strikes the impactor later in time as one moves radially along the impactor. Because the impactor is thinner as one moves radially outward, the velocity of the impactor is greater at the periphery than at the center. An acceptor explosive is positioned so that the impactor strikes the acceptor simultaneously. Consequently, a plane detonation wave is propagated through the acceptor explosive. 3 figs., 3 tabs.

  1. pCloud: A Cloud-based Power Market Simulation Environment

    SciTech Connect (OSTI)

    Rudkevich, Aleksandr; Goldis, Evgeniy

    2012-12-02

    This research conducted by the Newton Energy Group, LLC (NEG) is dedicated to the development of pCloud: a Cloud-based Power Market Simulation Environment. pCloud is offering power industry stakeholders the capability to model electricity markets and is organized around the Software as a Service (SaaS) concept -- a software application delivery model in which software is centrally hosted and provided to many users via the internet. During the Phase I of this project NEG developed a prototype design for pCloud as a SaaS-based commercial service offering, system architecture supporting that design, ensured feasibility of key architecture's elements, formed technological partnerships and negotiated commercial agreements with partners, conducted market research and other related activities and secured funding for continue development of pCloud between the end of Phase I and beginning of Phase II, if awarded. Based on the results of Phase I activities, NEG has established that the development of a cloud-based power market simulation environment within the Windows Azure platform is technologically feasible, can be accomplished within the budget and timeframe available through the Phase II SBIR award with additional external funding. NEG believes that pCloud has the potential to become a game-changing technology for the modeling and analysis of electricity markets. This potential is due to the following critical advantages of pCloud over its competition: - Standardized access to advanced and proven power market simulators offered by third parties. - Automated parallelization of simulations and dynamic provisioning of computing resources on the cloud. This combination of automation and scalability dramatically reduces turn-around time while offering the capability to increase the number of analyzed scenarios by a factor of 10, 100 or even 1000. - Access to ready-to-use data and to cloud-based resources leading to a reduction in software, hardware, and IT costs. - Competitive pricing structure, which will make high-volume usage of simulation services affordable. - Availability and affordability of high quality power simulators, which presently only large corporate clients can afford, will level the playing field in developing regional energy policies, determining prudent cost recovery mechanisms and assuring just and reasonable rates to consumers. - Users that presently do not have the resources to internally maintain modeling capabilities will now be able to run simulations. This will invite more players into the industry, ultimately leading to more transparent and liquid power markets.

  2. Two antenna, two pass interferometric synthetic aperture radar

    DOE Patents [OSTI]

    Martinez, Ana; Doerry, Armin W.; Bickel, Douglas L.

    2005-06-28

    A multi-antenna, multi-pass IFSAR mode utilizing data driven alignment of multiple independent passes can combine the scaling accuracy of a two-antenna, one-pass IFSAR mode with the height-noise performance of a one-antenna, two-pass IFSAR mode. A two-antenna, two-pass IFSAR mode can accurately estimate the larger antenna baseline from the data itself and reduce height-noise, allowing for more accurate information about target ground position locations and heights. The two-antenna, two-pass IFSAR mode can use coarser IFSAR data to estimate the larger antenna baseline. Multi-pass IFSAR can be extended to more than two (2) passes, thereby allowing true three-dimensional radar imaging from stand-off aircraft and satellite platforms.

  3. Iterative Self-Dual Reconstruction on Radar Image Recovery

    SciTech Connect (OSTI)

    Martins, Charles; Medeiros, Fatima; Ushizima, Daniela; Bezerra, Francisco; Marques, Regis; Mascarenhas, Nelson

    2010-05-21

    Imaging systems as ultrasound, sonar, laser and synthetic aperture radar (SAR) are subjected to speckle noise during image acquisition. Before analyzing these images, it is often necessary to remove the speckle noise using filters. We combine properties of two mathematical morphology filters with speckle statistics to propose a signal-dependent noise filter to multiplicative noise. We describe a multiscale scheme that preserves sharp edges while it smooths homogeneous areas, by combining local statistics with two mathematical morphology filters: the alternating sequential and the self-dual reconstruction algorithms. The experimental results show that the proposed approach is less sensitive to varying window sizes when applied to simulated and real SAR images in comparison with standard filters.

  4. Moving receive beam method and apparatus for synthetic aperture radar

    DOE Patents [OSTI]

    Kare, Jordin T. (San Ramon, CA)

    2001-01-01

    A method and apparatus for improving the performance of Synthetic Aperture Radar (SAR) systems by reducing the effect of "edge losses" associated with nonuniform receiver antenna gain. By moving the receiver antenna pattern in synchrony with the apparent motion of the transmitted pulse along the ground, the maximum available receiver antenna gain can be used at all times. Also, the receiver antenna gain for range-ambiguous return signals may be reduced, in some cases, by a large factor. The beam motion can be implemented by real-time adjustment of phase shifters in an electronically-steered phased-array antenna or by electronic switching of feed horns in a reflector antenna system.

  5. Operation Greenhouse. Scientific Director's report of atomic-weapon tests at Eniwetok, 1951. Annex 4. 1. Cloud studies. Part 1. Cloud physics. Part 2. Development of the atomic cloud. Part 3. Cloud-tracking photography

    SciTech Connect (OSTI)

    Anderson, C.E.; Gustafson, P.E.; Kellogg, W.W.; McKown, R.E.; McPherson, D.E.

    1985-09-01

    The cloud-physics project was primarily intended to fulfill a requirements for detailed information on the meteorological microstructure of atomic clouds. By means of a tracking and photographic network extending halfway around Eniwetok Atoll, the behavior of the first three clouds of Operation Greenhouse were observed and recorded. The rise of the fourth cloud was observed visually from only one site. The analysis of these observations, combined with information about the local weather conditions, gives a fairly complete picture of the development of each of the clouds. Particular emphasis was placed on the earlier phases of development, and the heights and sizes of the cloud parts have been determined as functions of time. A summary of important features of some previous atomic clouds are included for comparison.

  6. Phase coded, micro-power impulse radar motion sensor

    DOE Patents [OSTI]

    McEwan, T.E.

    1996-05-21

    A motion sensing, micro-power impulse radar MIR impresses on the transmitted signal, or the received pulse timing signal, one or more frequencies lower than the pulse repetition frequency, that become intermediate frequencies in a ``IF homodyne`` receiver. Thus, many advantages of classical RF receivers can be thereby be realized with ultra-wide band radar. The sensor includes a transmitter which transmits a sequence of electromagnetic pulses in response to a transmit timing signal at a nominal pulse repetition frequency. A receiver samples echoes of the sequence of electromagnetic pulses from objects within the field with controlled timing, in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The relative timing of the transmit timing signal and the receive timing signal is modulated between a first relative delay and a second relative delay at an intermediate frequency, causing the receiver to sample the echoes such that the time between transmissions of pulses in the sequence and samples by the receiver is modulated at the intermediate frequency. Modulation may be executed by modulating the pulse repetition frequency which drives the transmitter, by modulating the delay circuitry which controls the relative timing of the sample strobe, or by modulating amplitude of the transmitted pulses. The electromagnetic pulses will have a nominal center frequency related to pulse width, and the first relative delay and the second relative delay between which the timing signals are modulated, differ by less than the nominal pulse width, and preferably by about one-quarter wavelength at the nominal center frequency of the transmitted pulses. 5 figs.

  7. Phase coded, micro-power impulse radar motion sensor

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1996-01-01

    A motion sensing, micro-power impulse radar MIR impresses on the transmitted signal, or the received pulse timing signal, one or more frequencies lower than the pulse repetition frequency, that become intermediate frequencies in a "IF homodyne" receiver. Thus, many advantages of classical RF receivers can be thereby be realized with ultra-wide band radar. The sensor includes a transmitter which transmits a sequence of electromagnetic pulses in response to a transmit timing signal at a nominal pulse repetition frequency. A receiver samples echoes of the sequence of electromagnetic pulses from objects within the field with controlled timing, in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The relative timing of the transmit timing signal and the receive timing signal is modulated between a first relative delay and a second relative delay at an intermediate frequency, causing the receiver to sample the echoes such that the time between transmissions of pulses in the sequence and samples by the receiver is modulated at the intermediate frequency. Modulation may be executed by modulating the pulse repetition frequency which drives the transmitter, by modulating the delay circuitry which controls the relative timing of the sample strobe, or by modulating amplitude of the transmitted pulses. The electromagnetic pulses will have a nominal center frequency related to pulse width, and the first relative delay and the second relative delay between which the timing signals are modulated, differ by less than the nominal pulse width, and preferably by about one-quarter wavelength at the nominal center frequency of the transmitted pulses.

  8. mace-98.pdf

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    7 Cirrus Cloud Properties Derived from the First Year of Millimeter Wave Cloud Radar Data G. G. Mace Department of Meteorology University of Utah Salt Lake City, Utah E. E. Clothiaux Department of Meteorology The Pennsylvania State University University Park, Pennsylvania Introduction The representation of cirrus clouds in large-scale models continues to be a problem of considerable contemporary importance. These cloud systems occur over vast areas of the earth's surface, tend to occur in all

  9. Ultra-wideband short-pulse radar with range accuracy for short range detection

    DOE Patents [OSTI]

    Rodenbeck, Christopher T; Pankonin, Jeffrey; Heintzleman, Richard E; Kinzie, Nicola Jean; Popovic, Zorana P

    2014-10-07

    An ultra-wideband (UWB) radar transmitter apparatus comprises a pulse generator configured to produce from a sinusoidal input signal a pulsed output signal having a series of baseband pulses with a first pulse repetition frequency (PRF). The pulse generator includes a plurality of components that each have a nonlinear electrical reactance. A signal converter is coupled to the pulse generator and configured to convert the pulsed output signal into a pulsed radar transmit signal having a series of radar transmit pulses with a second PRF that is less than the first PRF.

  10. ARM - PI Product - Merged and corrected 915 MHz Radar Wind Profiler moments

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ProductsMerged and corrected 915 MHz Radar Wind Profiler moments ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Merged and corrected 915 MHz Radar Wind Profiler moments [ ARM research ] The radar wind profiler (RWP) present at the SGP central facility operates at 915 MHz and was reconfigured in early 2011, to collect key sets of measurements for precipitation and boundary layer studies. The RWP is

  11. Acoustic-wave sensor apparatus for analyzing a petroleum-based composition and sensing solidification of constituents therein

    DOE Patents [OSTI]

    Spates, J.J.; Martin, S.J.; Mansure, A.J.

    1997-08-26

    An acoustic-wave sensor apparatus and method are disclosed. The apparatus for analyzing a normally liquid petroleum-based composition includes at least one acoustic-wave device in contact with the petroleum-based composition for sensing or detecting the presence of constituents (e.g. paraffins or petroleum waxes) therein which solidify upon cooling of the petroleum-based composition below a cloud-point temperature. The acoustic-wave device can be a thickness-shear-mode device (also termed a quartz crystal microbalance), a surface-acoustic-wave device, an acoustic-plate-mode device or a flexural plate-wave device. Embodiments of the present invention can be used for measuring a cloud point, a pour point and/or a freeze point of the petroleum-based composition, and for determining a temperature characteristic of each point. Furthermore, measurements with the acoustic-wave sensor apparatus can be made off-line by using a sample having a particular petroleum-based composition; or in-situ with the petroleum-based composition contained within a pipeline or storage tank. The acoustic-wave sensor apparatus has uses in many different petroleum technology areas, including the recovery, transport, storage, refining and use of petroleum and petroleum-based products. 7 figs.

  12. Acoustic-wave sensor apparatus for analyzing a petroleum-based composition and sensing solidification of constituents therein

    DOE Patents [OSTI]

    Spates, James J. (Albuquerque, NM); Martin, Stephen J. (Albuquerque, NM); Mansure, Arthur J. (Albuquerque, NM)

    1997-01-01

    An acoustic-wave sensor apparatus and method. The apparatus for analyzing a normally liquid petroleum-based composition includes at least one acoustic-wave device in contact with the petroleum-based composition for sensing or detecting the presence of constituents (e.g. paraffins or petroleum waxes) therein which solidify upon cooling of the petroleum-based composition below a cloud-point temperature. The acoustic-wave device can be a thickness-shear-mode device (also termed a quartz crystal mircrobalance), a surface-acoustic-wave device, an acoustic-plate-mode device or a flexural plate-wave device. Embodiments of the present invention can be used for measuring a cloud point, a pour point and/or a freeze point of the petroleum-based composition, and for determining a temperature characteristic of each point. Furthermore, measurements with the acoustic-wave sensor apparatus can be made off-line by using a sample having a particular petroleum-based composition; or in-situ with the petroleum-based composition contained within a pipeline or storage tank. The acoustic-wave sensor apparatus has uses in many different petroleum technology areas, including the recover transport, storage, refining and use of petroleum and petroleum-based products.

  13. Deflagration Wave Profiles

    SciTech Connect (OSTI)

    Menikoff, Ralph

    2012-04-03

    Shock initiation in a plastic-bonded explosives (PBX) is due to hot spots. Current reactive burn models are based, at least heuristically, on the ignition and growth concept. The ignition phase occurs when a small localized region of high temperature (or hot spot) burns on a fast time scale. This is followed by a growth phase in which a reactive front spreads out from the hot spot. Propagating reactive fronts are deflagration waves. A key question is the deflagration speed in a PBX compressed and heated by a shock wave that generated the hot spot. Here, the ODEs for a steady deflagration wave profile in a compressible fluid are derived, along with the needed thermodynamic quantities of realistic equations of state corresponding to the reactants and products of a PBX. The properties of the wave profile equations are analyzed and an algorithm is derived for computing the deflagration speed. As an illustrative example, the algorithm is applied to compute the deflagration speed in shock compressed PBX 9501 as a function of shock pressure. The calculated deflagration speed, even at the CJ pressure, is low compared to the detonation speed. The implication of this are briefly discussed.

  14. Cirrus clouds in a global climate model with a statistical cirrus cloud scheme

    SciTech Connect (OSTI)

    Wang, Minghuai; Penner, Joyce E.

    2010-06-21

    A statistical cirrus cloud scheme that accounts for mesoscale temperature perturbations is implemented in a coupled aerosol and atmospheric circulation model to better represent both subgrid-scale supersaturation and cloud formation. This new scheme treats the effects of aerosol on cloud formation and ice freezing in an improved manner, and both homogeneous freezing and heterogeneous freezing are included. The scheme is able to better simulate the observed probability distribution of relative humidity compared to the scheme that was implemented in an older version of the model. Heterogeneous ice nuclei (IN) are shown to decrease the frequency of occurrence of supersaturation, and improve the comparison with observations at 192 hPa. Homogeneous freezing alone can not reproduce observed ice crystal number concentrations at low temperatures (<205 K), but the addition of heterogeneous IN improves the comparison somewhat. Increases in heterogeneous IN affect both high level cirrus clouds and low level liquid clouds. Increases in cirrus clouds lead to a more cloudy and moist lower troposphere with less precipitation, effects which we associate with the decreased convective activity. The change in the net cloud forcing is not very sensitive to the change in ice crystal concentrations, but the change in the net radiative flux at the top of the atmosphere is still large because of changes in water vapor. Changes in the magnitude of the assumed mesoscale temperature perturbations by 25% alter the ice crystal number concentrations and the net radiative fluxes by an amount that is comparable to that from a factor of 10 change in the heterogeneous IN number concentrations. Further improvements on the representation of mesoscale temperature perturbations, heterogeneous IN and the competition between homogeneous freezing and heterogeneous freezing are needed.

  15. ARM - Field Campaign - Cloud LAnd Surface Interaction Campaign...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Campaign Links CLASIC Website ARM Data Discovery Browse Data Related Campaigns CLASIC - SAM Support 2007.06.09, DeVore, SGP CLASIC - 9.4 GHz Phase Array Radar 2007.06.08, Kollias,...

  16. Wave Star Energy | Open Energy Information

    Open Energy Info (EERE)

    Star Energy Jump to: navigation, search Name: Wave Star Energy Place: Denmark Zip: DK-2920 Product: Denmark-based private wave device developer. References: Wave Star Energy1...

  17. Haynes Wave Basin | Open Energy Information

    Open Energy Info (EERE)

    Wave Basin Jump to: navigation, search Basic Specifications Facility Name Haynes Wave Basin Overseeing Organization Texas A&M (Haynes) Hydrodynamic Testing Facility Type Wave Basin...

  18. Tropical Cloud Properties and Radiative Heating Profiles

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Mather, James

    2008-01-15

    We have generated a suite of products that includes merged soundings, cloud microphysics, and radiative fluxes and heating profiles. The cloud microphysics is strongly based on the ARM Microbase value added product (Miller et al., 2003). We have made a few changes to the microbase parameterizations to address issues we observed in our initial analysis of the tropical data. The merged sounding product is not directly related to the product developed by ARM but is similar in that it uses the microwave radiometer to scale the radiosonde column water vapor. The radiative fluxes also differ from the ARM BBHRP (Broadband Heating Rate Profile) product in terms of the radiative transfer model and the sampling interval.

  19. Experiment to Characterize Tropical Cloud Systems

    SciTech Connect (OSTI)

    May, Peter T.; Mather, Jim H.; Jakob, Christian

    2005-08-02

    A major experiment to study tropical convective cloud systems and their impacts will take place around Darwin, Northern Australia in early 2006. The Tropical Warm Pool International Cloud Experiment (TWP-ICE) is a collaboration including the DOE ARM (Atmospheric Radiation Measurement) and ARM-UAV programs, NASA centers, the Australian Bureau of Meteorology, CSIRO, and universities in the USA, Australia, Japan, the UK, and Canada. TWP-ICE will be preceded in November/December 2004 by a collaborating European aircraft campaign involving the EU SCOUT-O3 and UK NERC ACTIVE projects. Detailed atmospheric measurements will be made in the Darwin area through the whole Austral summer, giving unprecedented coverage through the pre-monsoon and monsoon periods.

  20. Tropical Cloud Properties and Radiative Heating Profiles

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Mather, James

    We have generated a suite of products that includes merged soundings, cloud microphysics, and radiative fluxes and heating profiles. The cloud microphysics is strongly based on the ARM Microbase value added product (Miller et al., 2003). We have made a few changes to the microbase parameterizations to address issues we observed in our initial analysis of the tropical data. The merged sounding product is not directly related to the product developed by ARM but is similar in that it uses the microwave radiometer to scale the radiosonde column water vapor. The radiative fluxes also differ from the ARM BBHRP (Broadband Heating Rate Profile) product in terms of the radiative transfer model and the sampling interval.

  1. MAGIC: Marine ARM GPCI Investigation of Clouds

    SciTech Connect (OSTI)

    Lewis, ER; Wiscombe, WJ; Albrecht, BA; Bland, GL; Flagg, CN; Klein, SA; Kollias, P; Mace, G; Reynolds, RM; Schwartz, SE; Siebesma, AP; Teixeira, J; Wood, R; Zhang, M

    2012-10-03

    The second Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF2) will be deployed aboard the Horizon Lines cargo container ship merchant vessel (M/V) Spirit for MAGIC, the Marine ARM GPCI1 Investigation of Clouds. The Spirit will traverse the route between Los Angeles, California, and Honolulu, Hawaii, from October 2012 through September 2013 (except for a few months in the middle of this time period when the ship will be in dry dock). During this field campaign, AMF2 will observe and characterize the properties of clouds and precipitation, aerosols, and atmospheric radiation; standard meteorological and oceanographic variables; and atmospheric structure. There will also be two intensive observational periods (IOPs), one in January 2013 and one in July 2013, during which more detailed measurements of the atmospheric structure will be made.

  2. Elgen Wave | Open Energy Information

    Open Energy Info (EERE)

    Elgen Wave Jump to: navigation, search Name: Elgen Wave Region: United States Sector: Marine and Hydrokinetic Website: www.elgenwave.com This company is listed in the Marine and...

  3. The Dark Side of Cold Clouds

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Dark Side of Cold Clouds For original submission and image(s), see ARM Research Highlights http://www.arm.gov/science/highlights/ Research Highlight In research led by Pacific Northwest National Laboratory (PNNL), scientists sought to understand the atmospheric implications of tiny, highly irregular and chemically complex soot particles. The laboratory investigation, called the Soot Aerosol Aging Study (SAAS), examined the interactions of soot and a mix of other atmospheric particles using a

  4. Pollution Changes Clouds' Ice Crystal Genesis

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Pollution Changes Clouds' Ice Crystal Genesis For original submission and image(s), see ARM Research Highlights http://www.arm.gov/science/highlights/ Research Highlight Suspended high in the atmosphere, plentiful dust particles are fertile turf for growing ice. But, what are the optimal conditions for this crop? Researchers at Pacific Northwest National Laboratory (PNNL) found that miniscule particles of airborne dust, thought to be a perfect landing site for water vapor, are altered by the

  5. Filaments in simulations of molecular cloud formation

    SciTech Connect (OSTI)

    Gmez, Gilberto C.; Vzquez-Semadeni, Enrique

    2014-08-20

    We report on the filaments that develop self-consistently in a new numerical simulation of cloud formation by colliding flows. As in previous studies, the forming cloud begins to undergo gravitational collapse because it rapidly acquires a mass much larger than the average Jeans mass. Thus, the collapse soon becomes nearly pressureless, proceeding along its shortest dimension first. This naturally produces filaments in the cloud and clumps within the filaments. The filaments are not in equilibrium at any time, but instead are long-lived flow features through which the gas flows from the cloud to the clumps. The filaments are long-lived because they accrete from their environment while simultaneously accreting onto the clumps within them; they are essentially the locus where the flow changes from accreting in two dimensions to accreting in one dimension. Moreover, the clumps also exhibit a hierarchical nature: the gas in a filament flows onto a main, central clump but other, smaller-scale clumps form along the infalling gas. Correspondingly, the velocity along the filament exhibits a hierarchy of jumps at the locations of the clumps. Two prominent filaments in the simulation have lengths ?15 pc and masses ?600 M {sub ?} above density n ? 10{sup 3} cm{sup 3} (?2 10{sup 3} M {sub ?} at n > 50 cm{sup 3}). The density profile exhibits a central flattened core of size ?0.3 pc and an envelope that decays as r {sup 2.5} in reasonable agreement with observations. Accretion onto the filament reaches a maximum linear density rate of ?30 M {sub ?} Myr{sup 1} pc{sup 1}.

  6. Clouds Re-gathered by Wind Shear

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Re-gathered by Wind Shear For original submission and image(s), see ARM Research Highlights http://www.arm.gov/science/highlights/ Research Highlight When Pacific Northwest National Laboratory (PNNL) scientists looked for the culprit responsible for organizing storm clouds into strong weather systems, they pinned it on a fickle force. It turns out that wind shear at different vertical levels of the troposphere, well known for batting planes off their course, has strong and erratic effects on

  7. ARM - Feature Stories and Releases Article

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    8, 2009 [Facility News, Feature Stories and Releases] Thumbs-Up for Radar Design Reviews-Key Recovery Act Milestone Bookmark and Share Of the $60 million allocated to the ARM Climate Research Facility by the American Recovery and Reinvestment Act, nearly half that amount is designated for 18 new scanning radars as well as upgrades to the baseline ARM millimeter wave cloud radars (MMCR) located throughout the Facility. In November, ARM engineering staff led a series of preliminary design reviews

  8. Embracing the Cloud for Better Cyber Security

    SciTech Connect (OSTI)

    Shue, Craig A; Lagesse, Brent J

    2011-01-01

    The future of cyber security is inextricably tied to the future of computing. Organizational needs and economic factors will drive computing outcomes. Cyber security researchers and practitioners must recognize the path of computing evolution and position themselves to influence the process to incorporate security as an inherent property. The best way to predict future computing trends is to look at recent developments and their motivations. Organizations are moving towards outsourcing their data storage, computation, and even user desktop environments. This trend toward cloud computing has a direct impact on cyber security: rather than securing user machines, preventing malware access, and managing removable media, a cloud-based security scheme must focus on enabling secure communication with remote systems. This change in approach will have profound implications for cyber security research efforts. In this work, we highlight existing and emerging technologies and the limitations of cloud computing systems. We then discuss the cyber security efforts that would support these applications. Finally, we discuss the implications of these computing architecture changes, in particular with respect to malware and social engineering.

  9. Radar signal pre-processing to suppress surface bounce and multipath

    DOE Patents [OSTI]

    Paglieroni, David W; Mast, Jeffrey E; Beer, N. Reginald

    2013-12-31

    A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes that return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

  10. DOE/SC-ARM-12-006 ARM Climate Research Facility Radar Operations...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    6 ARM Climate Research Facility Radar Operations Plan May 2012 DISCLAIMER This report was prepared as an account of work sponsored by the U.S. Government. Neither the United States...

  11. Vertical air motions over the Tropical Western Pacific for validating cloud resolving and regional models

    SciTech Connect (OSTI)

    Williams, Christopher R.

    2015-03-16

    The objective of this project was to estimate the vertical air motion using Doppler velocity spectra from two side-by-side vertically pointing radars. The retrieval technique was applied to two different sets of radars. This first set was 50- and 920-MHz vertically pointing radars near Darwin, Australia. The second set was 449-MHz and 2.8-GHz vertically pointing radars deployed at SGP for MC3E. The retrieval technique uses the longer wavelength radar (50 or 449 MHz) to observe both the vertical air motion and precipitation motion while the shorter wavelength radar (920 MHz or 2.8 GHz) observes just the precipitation motion. By analyzing their Doppler velocity spectra, the precipitation signal in the 920 MHz or 2.8 GHz radar is used to mask-out the precipitation signal in the 50 or 449 MHz radar spectra, leaving just the vertical air motion signal.

  12. Cloud and aerosol characterization for the ARM central facility: Multiple remote sensor techniques development

    SciTech Connect (OSTI)

    Sassen, K.

    1992-04-30

    This research project designed to investigate how atmospheric remote sensing technology can best be applied to the characterization of the cloudy atmosphere. Our research program addresses basic atmospheric remote sensing questions, but at the same time is clearly directed toward providing information crucial to the ARM (Atmospheric Remote Sensing) program and for application to the Clouds and Radiation Testbed (CART). The instrumentation that is being brought into play includes a variety of art-of-the-art sensors. Available at NOAA WPL are polarization Doppler K{sub a}-band (0.86 mm) and X-band (3.2 cm) radars, a C0{sub 2}(10.6 {mu}m) Doppler lidar with sequential ' polarization measurement capabilities, a three-channel (20.6, 31.65 and 90 GHz) microwave radiometer, and variety of visible and infrared radiometers. Instrumentation at the University of Utah Facility for Atmospheric Remote Sensing (FARS) includes a polarization ruby (0.643 {mu}m) lidar, a narrow-beam (0.14{degree}) mid-infrared (9.5--11.5 {mu}m) radiometer coaligned with the lidar, several other radiometers in the visible and infrared spectral regions, and an advanced two-color (1.06 and 0.532 {mu}m), four-channel Polarization Diversity Lidar (PDL) and all-sky video imaging system that have only recently been developed under the ARM IDP.

  13. Intercomparison of the Cloud Water Phase among Global Climate Models

    SciTech Connect (OSTI)

    Komurcu, Muge; Storelvmo, Trude; Tan, Ivy; Lohmann, U.; Yun, Yuxing; Penner, Joyce E.; Wang, Yong; Liu, Xiaohong; Takemura, T.

    2014-03-27

    Mixed-phase clouds (clouds that consist of both cloud droplets and ice crystals) are frequently present in the Earths atmosphere and influence the Earths energy budget through their radiative properties, which are highly dependent on the cloud water phase. In this study, the phase partitioning of cloud water is compared among six global climate models (GCMs) and with Cloud and Aerosol Lidar with Orthogonal Polarization retrievals. It is found that the GCMs predict vastly different distributions of cloud phase for a given temperature, and none of them are capable of reproducing the spatial distribution or magnitude of the observed phase partitioning. While some GCMs produced liquid water paths comparable to satellite observations, they all failed to preserve sufficient liquid water at mixed-phase cloud temperatures. Our results suggest that validating GCMs using only the vertically integrated water contents could lead to amplified differences in cloud radiative feedback. The sensitivity of the simulated cloud phase in GCMs to the choice of heterogeneous ice nucleation parameterization is also investigated. The response to a change in ice nucleation is quite different for each GCM, and the implementation of the same ice nucleation parameterization in all models does not reduce the spread in simulated phase among GCMs. The results suggest that processes subsequent to ice nucleation are at least as important in determining phase and should be the focus of future studies aimed at understanding and reducing differences among the models.

  14. Laser radar VI; Proceedings of the Meeting, Los Angeles, CA, Jan. 23-25, 1991

    SciTech Connect (OSTI)

    Becherer, R.J.

    1991-01-01

    Topics presented include lidar wind shear detection for commercial aircraft, centroid tracking of range-Doppler images, an analytic approach to centroid performance analysis, simultaneous active/passive IR vehicle detection, and resolution limits for high-resolution imaging lidar. Also presented are laser velocimetry applications, the application of laser radar to autonomous spacecraft landing, 3D laser radar simulation for autonomous spacecraft landing, and ground based CW atmospheric Doppler lidar performamce modeling.

  15. Heating Profiles Derived From Cm-wavelength Radar During TWP-ICE

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Heating Profiles Derived From Cm-wavelength Radar During TWP-ICE Heating Profiles Derived From Cm-wavelength Radar During TWP-ICE Courtney Schumacher and Kaycee Frederick Courtney Schumacher and Kaycee Frederick Department of Atmospheric Sciences Department of Atmospheric Sciences Texas A&M University Texas A&M University LATENT HEATING ESTIMATES PRELIMINARY RADIATIVE HEATING ESTIMATES Shallow (< 8km) convection Deep convection Stratiform rain SC 4% SC 37% SC 11% SF 24% SF 9% SF 8% DC

  16. Property:Maximum Wave Height(m) at Wave Period(s) | Open Energy...

    Open Energy Info (EERE)

    at Wave Period(s) Jump to: navigation, search Property Name Maximum Wave Height(m) at Wave Period(s) Property Type String Pages using the property "Maximum Wave Height(m) at Wave...

  17. Charge Density Wave Compounds

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Fisher Research Group Layered Chalcogenides 29 February 2008 Controlling the Wave by Brad Plummer, SLAC Communications Stanford University researchers working in part at SSRL have discovered a novel set of properties pertaining to a compound of materials called tritellurides. These compounds, composed of three atoms of tellurium and a single atom of one of the rare earth elements, demonstrate unique electronic properties that can be controlled by altering the temperature of the material. The

  18. Vertical microphysical profiles of convective clouds as a tool for obtaining aerosol cloud-mediated climate forcings

    SciTech Connect (OSTI)

    Rosenfeld, Daniel

    2015-12-23

    Quantifying the aerosol/cloud-mediated radiative effect at a global scale requires simultaneous satellite retrievals of cloud condensation nuclei (CCN) concentrations and cloud base updraft velocities (Wb). Hitherto, the inability to do so has been a major cause of high uncertainty regarding anthropogenic aerosol/cloud-mediated radiative forcing. This can be addressed by the emerging capability of estimating CCN and Wb of boundary layer convective clouds from an operational polar orbiting weather satellite. Our methodology uses such clouds as an effective analog for CCN chambers. The cloud base supersaturation (S) is determined by Wb and the satellite-retrieved cloud base drop concentrations (Ndb), which is the same as CCN(S). Developing and validating this methodology was possible thanks to the ASR/ARM measurements of CCN and vertical updraft profiles. Validation against ground-based CCN instruments at the ARM sites in Oklahoma, Manaus, and onboard a ship in the northeast Pacific showed a retrieval accuracy of ±25% to ±30% for individual satellite overpasses. The methodology is presently limited to boundary layer not raining convective clouds of at least 1 km depth that are not obscured by upper layer clouds, including semitransparent cirrus. The limitation for small solar backscattering angles of <25º restricts the satellite coverage to ~25% of the world area in a single day. This methodology will likely allow overcoming the challenge of quantifying the aerosol indirect effect and facilitate a substantial reduction of the uncertainty in anthropogenic climate forcing.

  19. A statistical study of EMIC waves observed by Cluster. 1. Wave properties. EMIC Wave Properties

    SciTech Connect (OSTI)

    Allen, R. C.; Zhang, J. -C.; Kistler, L. M.; Spence, H. E.; Lin, R. -L.; Klecker, B.; Dunlop, M. W.; Andr, M.; Jordanova, V. K.

    2015-07-23

    Electromagnetic ion cyclotron (EMIC) waves are an important mechanism for particle energization and losses inside the magnetosphere. In order to better understand the effects of these waves on particle dynamics, detailed information about the occurrence rate, wave power, ellipticity, normal angle, energy propagation angle distributions, and local plasma parameters are required. Previous statistical studies have used in situ observations to investigate the distribution of these parameters in the magnetic local time versus L-shell (MLT-L) frame within a limited magnetic latitude (MLAT) range. In our study, we present a statistical analysis of EMIC wave properties using 10 years (20012010) of data from Cluster, totaling 25,431 min of wave activity. Due to the polar orbit of Cluster, we are able to investigate EMIC waves at all MLATs and MLTs. This allows us to further investigate the MLAT dependence of various wave properties inside different MLT sectors and further explore the effects of Shabansky orbits on EMIC wave generation and propagation. Thus, the statistical analysis is presented in two papers. OUr paper focuses on the wave occurrence distribution as well as the distribution of wave properties. The companion paper focuses on local plasma parameters during wave observations as well as wave generation proxies.

  20. A statistical study of EMIC waves observed by Cluster. 1. Wave properties. EMIC Wave Properties

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Allen, R. C.; Zhang, J. -C.; Kistler, L. M.; Spence, H. E.; Lin, R. -L.; Klecker, B.; Dunlop, M. W.; André, M.; Jordanova, V. K.

    2015-07-23

    Electromagnetic ion cyclotron (EMIC) waves are an important mechanism for particle energization and losses inside the magnetosphere. In order to better understand the effects of these waves on particle dynamics, detailed information about the occurrence rate, wave power, ellipticity, normal angle, energy propagation angle distributions, and local plasma parameters are required. Previous statistical studies have used in situ observations to investigate the distribution of these parameters in the magnetic local time versus L-shell (MLT-L) frame within a limited magnetic latitude (MLAT) range. In our study, we present a statistical analysis of EMIC wave properties using 10 years (2001–2010) of datamore » from Cluster, totaling 25,431 min of wave activity. Due to the polar orbit of Cluster, we are able to investigate EMIC waves at all MLATs and MLTs. This allows us to further investigate the MLAT dependence of various wave properties inside different MLT sectors and further explore the effects of Shabansky orbits on EMIC wave generation and propagation. Thus, the statistical analysis is presented in two papers. OUr paper focuses on the wave occurrence distribution as well as the distribution of wave properties. The companion paper focuses on local plasma parameters during wave observations as well as wave generation proxies.« less

  1. ARM - Publications: Science Team Meeting Documents: Cirrus Cloud

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Measurements by the UAF Polarization Diversity Lidar during M-PACE Cirrus Cloud Measurements by the UAF Polarization Diversity Lidar during M-PACE Sassen, Kenneth University of Alaska Fairbanks Zhu, Jiang UAF During the final week of the September-October 2004 Mixed-Phase Cloud Experiment (M-PACE) conducted in and around the North Slope of Alaska (NSA) Atmospheric Radiation Measurement (ARM) site in Barrow, Alaska, cirrus clouds were unexpectedly prevalent. Overcoming earlier adversity, the

  2. Clearing up concerns about cloud computing and genomics research | Argonne

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    National Laboratory Clearing up concerns about cloud computing and genomics research November 5, 2013 Tweet EmailPrint Cloud computing has become a popular option for scientists wanting on-demand access to increased capacity and capabilities, without having to invest in costly new hardware, storage, or other infrastructure. Genomics researchers, who produce enormous amounts of data thanks to new DNA sequencing technology, have begun to recognize the potential benefits of moving to the cloud.

  3. Comparison of Parameterized Cloud Variability to ARM Data

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Comparison of Parameterized Cloud Variability to ARM Data S. A. Klein National Oceanic and Atmospheric Administration Geophysical Fluid Dynamics Laboratory Princeton, New Jersey J. R. Norris Scripps Institute of Oceanography University of California La Jolla, California Abstract Cloud parameterizations in large-scale models often try to predict the amount of sub-grid scale variability in cloud properties to address the significant non-linear effects of radiation and precipitation. Statistical

  4. Continental Liquid-phase Stratus Clouds at SGP: Meteorological Influences

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and Relationship to Adiabacity Continental Liquid-phase Stratus Clouds at SGP: Meteorological Influences and Relationship to Adiabacity Kim, Byung-Gon Kangnung National University Schwartz, Stephen Brookhaven National Laboratory Miller, Mark Brookhaven National Laboratory Min, Qilong State University of New York at Albany Category: Cloud Properties The microphysical properties of continental stratus clouds observed over SGP appear to be substantially influenced by micrometeorological

  5. Can Cloud Computing Address the Scientific Computing Requirements for DOE

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Researchers? Well, Yes, No and Maybe Can Cloud Computing Address the Scientific Computing Requirements for DOE Researchers? Well, Yes, No and Maybe Can Cloud Computing Address the Scientific Computing Requirements for DOE Researchers? Well, Yes, No and Maybe January 30, 2012 Jon Bashor, Jbashor@lbl.gov, +1 510-486-5849 Magellan1.jpg Magellan at NERSC After a two-year study of the feasibility of cloud computing systems for meeting the ever-increasing computational needs of scientists,

  6. ARM - PI Product - Atmospheric State, Cloud Microphysics & Radiative Flux

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ProductsAtmospheric State, Cloud Microphysics & Radiative Flux ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Atmospheric State, Cloud Microphysics & Radiative Flux [ ARM Principal Investigator (PI) Data Product ] Atmospheric thermodynamics, cloud properties, radiative fluxes and radiative heating rates for the ARM Southern Great Plains (SGP) site. The data represent a characterization of the

  7. ARM - Field Campaign - Macquarie Island Cloud and Radiation Experiment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (MICRE) govCampaignsMacquarie Island Cloud and Radiation Experiment (MICRE) Campaign Links Science Plan Backgrounder Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Macquarie Island Cloud and Radiation Experiment (MICRE) 2016.03.01 - 2018.03.31 Lead Scientist : Roger Marchand Abstract Clouds over the Southern Ocean are poorly represented in present day reanalysis products and global climate model simulations. Errors in

  8. Cloud-Based Transportation Management System Delivers Savings | Department

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    of Energy Cloud-Based Transportation Management System Delivers Savings Cloud-Based Transportation Management System Delivers Savings October 21, 2014 - 1:53pm Addthis DOE's cloud based transportation management system (ATLAS) offers dramatically enhanced capabilities and modernization. ATLAS provides a powerful user-friendly system built to allow access to information to meet transportation needs. Its processes promote regulatory compliance, while providing access to qualified carriers and

  9. MAGIC Cloud Properties from Zenith Radiance Data Final Campaign Summary

    SciTech Connect (OSTI)

    Chiu, J. -Y.C.; Gregory, L.; Wagener, R.

    2016-01-01

    Cloud droplet size and optical depth are the most fundamental properties for understanding cloud formation, dissipation and interactions with aerosol and drizzle. They are also a crucial determinant of Earth’s radiative and water-energy balances. However, these properties are poorly predicted in climate models. As a result, the response of clouds to climate change is one of the major sources of uncertainty in climate prediction.

  10. ARM - Field Campaign - Aerosol and Cloud Experiments in the Eastern...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    horizontal variabilities of aerosol, trace gases, cloud, drizzle, and atmospheric thermodynamics are critically needed for understanding and quantifying the budget of MBL aerosol,...

  11. Chameleon: A Computer Science Testbed as Application of Cloud...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Chameleon: A Computer Science Testbed as Application of Cloud Computing Event Sponsor: Mathematics and Computing Science Brownbag Lunch Start Date: Dec 15 2015 - 12:00pm Building...

  12. Liquid Water the Key to Arctic Cloud Radiative Closure

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Water the Key to Arctic Cloud Radiative Closure For original submission and image(s), see ARM Research Highlights http:www.arm.govsciencehighlights Research Highlight...

  13. Stereo Photogrammetry Reveals Substantial Drag on Cloud Thermals

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    sciencehighlights Research Highlight Fast updrafts within clouds can generate hail, lightning, and tornadoes at the surface, as well as clear-air turbulence that pose...

  14. ARM - Publications: Science Team Meeting Documents: Interpretation of cloud

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    structure anomalies over the tropical Pacific during the 1997/98 El Nino Interpretation of cloud structure anomalies over the tropical Pacific during the 1997/98 El Nino Cess, Robert State University of New York at Stony Brook Sun, Moguo State University of New York at Stony Brook The CERES/TRMM single satellite footprint (SSF) dataset, available for January 1998 to August 1998, provides not only radiometric data, but also data for cloud fraction, cloud top pressure and cloud optical depth.

  15. ARM - Field Campaign - FIRE-Arctic Cloud Experiment/SHEBA

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in the Arctic, to measure the BRDF and albedos of various surfaces (ice, snow and tundra) and various cloud types, and to obtain these measurements whenever possible either...

  16. ARM - Publications: Science Team Meeting Documents: Clouds in...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Clouds in the Darwin area and their relation to large-scale conditions Jakob, Christian BMRC Hoeglund, Sofia Lulea University of Technology This poster shows a climatological...

  17. Posters Ship-Based Measurements of Cloud Optical Properties

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the optical properties of MBL clouds using measurements taken on the NOAA research vessel Malcom Baldrige. We seek the relationship between optical depth and liquid water because...

  18. The relationship between interannual and long-term cloud feedbacks...

    Office of Scientific and Technical Information (OSTI)

    The relationship between interannual and long-term cloud feedbacks Citation Details In-Document Search This content will become publicly available on December 11, 2016 Title: The ...

  19. RACORO continental boundary layer cloud investigations. 2. Large-eddy

    Office of Scientific and Technical Information (OSTI)

    simulations of cumulus clouds and evaluation with in-situ and ground-based observations (Journal Article) | SciTech Connect 2. Large-eddy simulations of cumulus clouds and evaluation with in-situ and ground-based observations Citation Details In-Document Search This content will become publicly available on June 19, 2016 Title: RACORO continental boundary layer cloud investigations. 2. Large-eddy simulations of cumulus clouds and evaluation with in-situ and ground-based observations A

  20. Single-Column Modeling A Stratiform Cloud Parameterization for...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    parameterization originally developed for mesoscale cloud models (Tripoli and Cotton 1980, Cotton et al. 1982 and 1986, Meyers et al. 1992). These approximations are...

  1. Surface based remote sensing of aerosol-cloud interactions

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of a range of proxies for cloud condensation nuclei, ranging from surface measurements of light scattering and accumulation mode number concentration, to lidar-measured extinction...

  2. The Tropical Warm Pool International Cloud Experiment: Overview

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The Tropical Warm Pool International Cloud Experiment: Overview May, Peter Bureau or Meteorology Research Centre Mather, James Pacific Northwest National Laboratory Jakob,...

  3. Sensitivity of Boundary-layer and Deep Convective Cloud Simulations...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cloud Simulations to Vertical Resolution Cheng, Anning Langley Research Center Xu, Kuan-Man NASA Langley Research Center Category: Modeling This study investigates the effects of...

  4. Testing Statistical Cloud Scheme Ideas in the GFDL Climate Model

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Testing Statistical Cloud Scheme Ideas in the GFDL Climate Model Klein, Stephen Lawrence Livermore National Laboratory Pincus, Robert NOAA-CIRES Climate Diagnostics Center...

  5. Atmospheric Rivers Coming to a Cloud Near You

    SciTech Connect (OSTI)

    Leung, Ruby

    2014-03-29

    Learn about the ARM Cloud Aerosol Precipitation Experiment (ACAPEX) field campaign in this short video. Ruby Leung, PNNL's lead scientist on this campaign's observational strategy to monitor precipitation.

  6. Preliminary Studies on the Variational Assimilation of Cloud...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    for both cloud properties and surface radiative fluxes have been used in our feasibility studies. The assimilation of those observations has shown the capability of the...

  7. Fundamental to the Cloud Land Surface Interaction Campaign (CLASIC...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in agriculture ranging from more accurate weather forecasting to improved water management decisions and crop yield estimation. CLASIC CLASIC - - LAND LAND Cloud and Land...

  8. A Comparison of Cirrus Cloud Visible Optical Depth Derived from...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Comparison of Cirrus Cloud Visible Optical Depth Derived from Lidar Lo, Chaomei Pacific Northwest National Laboratory Comstock, Jennifer Pacific Northwest National Laboratory...

  9. Layered Atlantic Smoke Interactions with Clouds (LASIC) Science...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... Colocated smoke and clouds over the remote ocean represent a regime of significant ... that will be helpful in resolving current uncertainties in the aging and transport ...

  10. ARM - Field Campaign - Cloud, Aerosol, and Complex Terrain Interaction...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    This range of environmental conditions and cloud properties coupled with a high frequency of events makes this an ideal location for improving our understanding of...

  11. Simulations of Midlatitude Frontal Clouds by Single-Column and...

    Office of Scientific and Technical Information (OSTI)

    condensates due to differences in parameterizations, however, the differences among inter-compared models are smaller in the CRMs than the SCMs. While the CRM-produced clouds...

  12. Examining How Radiative Fluxes Are Affected by Cloud and Particle...

    Office of Science (SC) Website

    the Earth will change as emissions from fossil fuel combustion change, climate models calculate a complex and changing mix of clouds and emissions that interact with solar energy. ...

  13. Cluster Analysis of Cloud Regimes and Characteristic Dynamics...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cluster Analysis of Cloud Regimes and Characteristic Dynamics of Mid-Latitude Synoptic Systems N. D. Gordon and J. R. Norris Scripps Institution of Oceanography University of...

  14. Clouds, Aerosols and Precipitation in the Marine Boundary Layer...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Framework, extend to investigation of aerosol-cloud interactions in models - Ensemble Kalman Filter (DART) Satellite activities with CAP-MBL Minnis: CAP-MBL subset MBL depth,...

  15. Intersecting Cold Pools: Convective Cloud Organization by Cold...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Intersecting Cold Pools: Convective Cloud Organization by Cold Pools over Tropical Ocean For original submission and image(s), see ARM Research Highlights http:www.arm.gov...

  16. ARM - Field Campaign - MASRAD: Cloud Condensate Nuclei Chemistry...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cloud Condensate Nuclei Chemistry Measurements Campaign Links AMF Point Reyes Website ARM Data Discovery Browse Data Related Campaigns MArine Stratus Radiation Aerosol and Drizzle...

  17. ARM - Field Campaign - Cirrus Clouds and Aerosol Properties Campaign

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govCampaignsCirrus Clouds and Aerosol Properties Campaign ARM Data Discovery Browse Data Related Campaigns Vaisala Laser Ceilometer CL51 Demonstration 2013.11.14, Winston, SGP...

  18. ARM - Field Campaign - MASRAD: Pt. Reyes Stratus Cloud and Drizzle...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govCampaignsMASRAD: Pt. Reyes Stratus Cloud and Drizzle Study Campaign Links AMF Point Reyes Website ARM Data Discovery Browse Data Related Campaigns MArine Stratus Radiation...

  19. ARM - Field Campaign - Colorado: The Storm Peak Lab Cloud Property...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The Storm Peak Lab Cloud Property Validation Experiment (STORMVEX) Campaign Links STORMVEX Website ARM Data Discovery Browse Data Related Campaigns Colorado: CFHCMH Deployment to...

  20. Remote Spectroscopic Sounding of Liquid Water Path in Thick Clouds...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, the original methodology of sounding of dense clouds has been under development 1-3. The methodology...

  1. MBL Drizzle Properties and Their Impact on Cloud Property Retrieval

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    layer drizzle properties and their impact on cloud property retrieval." Atmospheric Measurement Techniques, 8, doi:10.5194amt-8-3555-2015. Contributors Xiquan Dong,...

  2. Testing a Cloud Condensation Nuclei Remote Sensing Method

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    a Cloud Condensation Nuclei Remote Sensing Method S. J. Ghan Climate Physics Pacific Northwest National Laboratory Richland, Washington D. R. Collin Department of Atmospheric...

  3. arm_stm_2007_revercomb_poster_cloud.ppt

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AERI Derived Cloud Properties David Tobin, Lori Borg, David Turner, Robert Holz, Daniel DeSlover, Hank Revercomb, Bob Knuteson, Leslie Moy, Ed Eloranta, Jun Li Space Science...

  4. A Lidar View of Clouds in Southeastern China

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Lidar View of Clouds in Southeastern China For original submission and image(s), see ARM Research Highlights http:www.arm.govsciencehighlights Research Highlight From May 2008...

  5. Sensitivity of Radiative Fluxes and Heating Rates to Cloud Microphysic...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Sensitivity of Radiative Fluxes and Heating Rates to Cloud Microphysics S. F. Iacobellis and R. C. J. Somerville Scripps Institution of Oceanography University of California, San...

  6. The Radiative Role of Free Tropospheric Aerosols and Marine Clouds...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: The Radiative Role of Free Tropospheric Aerosols and Marine Clouds over the Central North Atlantic Citation Details In-Document Search Title: The Radiative Role...

  7. Cloud Lake, Florida: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Cloud Lake, Florida: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 26.6761772, -80.0739308 Show Map Loading map... "minzoom":false,"mappingse...

  8. ARM - Publications: Science Team Meeting Documents: Clouds and...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Clouds and radiation in the Arctic coastal system - effects of local heterogeneity Key, Erica University of Miami, RSMAS Minnett, Peter University of Miami Improving our...

  9. Cloud-Resolving Model Simulation and Mosaic Treatment of Subgrid...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The development of cloud-resolving models (CRMs) and the extensive Atmospheric Radiation Measurements (ARMs) provide a unique opportunity for shading some lights on this problem. ...

  10. RACORO continental boundary layer cloud investigations. 2. Large...

    Office of Scientific and Technical Information (OSTI)

    The case is based on observations obtained during the RACORO Campaign (Routine AtmosphericRadiation Measurement ARM Aerial Facility AAF Clouds with Low Optical Water Depths ...

  11. Testing AGCM-Predicted Cloud and Radiation Properties with ARM...

    Office of Scientific and Technical Information (OSTI)

    evaluate treatment of clouds and radiation in an atmospheric global climate model (AGCM) using long-term observations from the Atmospheric Radiation Measurement (ARM) program. ...

  12. Atmospheric Rivers Coming to a Cloud Near You

    ScienceCinema (OSTI)

    Leung, Ruby

    2014-06-12

    Learn about the ARM Cloud Aerosol Precipitation Experiment (ACAPEX) field campaign in this short video. Ruby Leung, PNNL's lead scientist on this campaign's observational strategy to monitor precipitation.

  13. Lynx: A High-Resolution Synthetic Aperture Radar

    SciTech Connect (OSTI)

    Doerry, A.W.; Hensley, W.H.; Pace, F.; Stence, J.; Tsunoda, S.I.; Walker, B.C.; Woodring, M.

    1999-03-08

    Lynx is a high resolution, synthetic aperture radar (SAR) that has been designed and built by Sandia National Laboratories in collaboration with General Atomics (GA). Although Lynx may be operated on a wide variety of manned and unmanned platforms, it is primarily intended to be fielded on unmanned aerial vehicles. In particular, it may be operated on the Predator, I-GNAT, or Prowler II platforms manufactured by GA Aeronautical Systems, Inc. The Lynx production weight is less than 120 lb. and has a slant range of 30 km (in 4 mm/hr rain). It has operator selectable resolution and is capable of 0.1 m resolution in spotlight mode and 0.3 m resolution in stripmap mode. In ground moving target indicator mode, the minimum detectable velocity is 6 knots with a minimum target cross-section of 10 dBsm. In coherent change detection mode, Lynx makes registered, complex image comparisons either of 0.1 m resolution (minimum) spotlight images or of 0.3 m resolution (minimum) strip images. The Lynx user interface features a view manager that allows it to pan and zoom like a video camera. Lynx was developed under corporate finding from GA and will be manufactured by GA for both military and commercial applications. The Lynx system architecture will be presented and some of its unique features will be described. Imagery at the finest resolutions in both spotlight and strip modes have been obtained and will also be presented.

  14. Evaluate the Effect of Upper-Level Cirrus Clouds on Satellite Retrievals of Low-Level Cloud Droplet Effective Radius

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the Effect of Upper-Level Cirrus Clouds on Satellite Retrievals of Low-Level Cloud Droplet Effective Radius F.-L. Chang and Z. Li Earth System Science Interdisciplinary Center University of Maryland College Park, Maryland Z. Li Department of Meteorology University of Maryland College Park, Maryland Introduction The earth's radiation budget is sensitive to changes in the microphysical properties of low-level stratiform clouds. Their extensive coverage can significantly reduce the solar energy

  15. SUPERGIANT SHELLS AND MOLECULAR CLOUD FORMATION IN THE LARGE MAGELLANIC CLOUD

    SciTech Connect (OSTI)

    Dawson, J. R.; Dickey, John M.; McClure-Griffiths, N. M.; Wong, T.; Hughes, A.; Fukui, Y.; Kawamura, A.

    2013-01-20

    We investigate the influence of large-scale stellar feedback on the formation of molecular clouds in the Large Magellanic Cloud (LMC). Examining the relationship between H I and {sup 12}CO(J = 1-0) in supergiant shells (SGSs), we find that the molecular fraction in the total volume occupied by SGSs is not enhanced with respect to the rest of the LMC disk. However, the majority of objects ({approx}70% by mass) are more molecular than their local surroundings, implying that the presence of a supergiant shell does on average have a positive effect on the molecular gas fraction. Averaged over the full SGS sample, our results suggest that {approx}12%-25% of the molecular mass in supergiant shell systems was formed as a direct result of the stellar feedback that created the shells. This corresponds to {approx}4%-11% of the total molecular mass of the galaxy. These figures are an approximate lower limit to the total contribution of stellar feedback to molecular cloud formation in the LMC, and constitute one of the first quantitative measurements of feedback-triggered molecular cloud formation in a galactic system.

  16. Short-Term Arctic Cloud Statistics at NSA from the Infrared Cloud...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    10-20% 20-30% 30-40% 40-50% 50-60% 60-70% 70-80% 80-90% 90-100% Figure 4. Monthly cloud statistics. (March data limited to the last two weeks) Acknowledgment The ICI system was...

  17. Cloud feedback studies with a physics grid

    SciTech Connect (OSTI)

    Dipankar, Anurag; Stevens, Bjorn

    2013-02-07

    During this project the investigators implemented a fully parallel version of dual-grid approach in main frame code ICON, implemented a fully conservative first-order interpolation scheme for horizontal remapping, integrated UCLA-LES micro-scale model into ICON to run parallely in selected columns, and did cloud feedback studies on aqua-planet setup to evaluate the classical parameterization on a small domain. The micro-scale model may be run in parallel with the classical parameterization, or it may be run on a "physics grid" independent of the dynamics grid.

  18. Integrated Cloud Based Environmental Data Management System

    Office of Environmental Management (EM)

    NNSA U N C L A S S I F I E D Integrated Cloud Based Environmental Data Management System Penny Gomez (pgomez@lanl.gov) Los Alamos National Laboratory Data System Integration Project Leader LA-UR-12-21030 Chris EchoHawk (echohawk@lanl.gov) Los Alamos National Laboratory Environmental Data and Analysis Group Leader Karen Schultz Paige (ksp@lanl.gov) Los Alamos National Laboratory Intellus Project Leader Operated by Los Alamos National Security, LLC for the U.S. Department of Energy's NNSA U N C L

  19. Cloud microphysical relationships and their implication on entrainment and mixing mechanism for the stratocumulus clouds measured during the VOCALS project

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yum, Seong Soo; Wang, Jian; Liu, Yangang; Senum, Gunnar; Springston, Stephen; McGraw, Robert; Yeom, Jae Min

    2015-05-27

    Cloud microphysical data obtained from G-1 aircraft flights over the southeastern pacific during the VOCALS-Rex field campaign were analyzed for evidence of entrainment mixing of dry air from above cloud top. Mixing diagram analysis was made for the horizontal flight data recorded at 1 Hz and 40 Hz. The dominant observed feature, a positive relationship between cloud droplet mean volume (V) and liquid water content (L), suggested occurrence of homogeneous mixing. On the other hand, estimation of the relevant scale parameters (i.e., transition length scale and transition scale number) consistently indicated inhomogeneous mixing. Importantly, the flight altitudes of the measurementsmore » were significantly below cloud top. We speculate that mixing of the entrained air near the cloud top may have indeed been inhomogeneous; but due to vertical circulation mixing, the correlation between V and L became positive at the measurement altitudes in mid-level of clouds, because during their descent, cloud droplets evaporate, faster in more diluted cloud parcels, leading to a positive correlation between V and L regardless of the mixing mechanism near the cloud top.« less

  20. Spin waves in the (

    SciTech Connect (OSTI)

    Lipscombe, O. J.; Chen, G. F.; Fang, Chen; Perring, T. G.; Abernathy, Douglas L; Christianson, Andrew D; Egami, Takeshi; Wang, Nanlin; Hu, Jiangping; Dai, Pengcheng

    2011-01-01

    We use neutron scattering to show that spin waves in the iron chalcogenide Fe{sub 1.05}Te display novel dispersion clearly different from both the first principles density functional calculations and recent observations in the related iron pnictide CaFe{sub 2}As{sub 2}. By fitting to a Heisenberg Hamiltonian, we find that although the nearest-neighbor exchange couplings in the two systems are quite different, their next-nearest-neighbor (NNN) couplings are similar. This suggests that superconductivity in the pnictides and chalcogenides share a common magnetic origin that is intimately associated with the NNN magnetic coupling between the irons.