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Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Evaluation of Tropical Cirrus Cloud Properties and Dynamical...  

NLE Websites -- All DOE Office Websites (Extended Search)

through the TTL into the stratosphere. The ability of large-scale models to correctly forecast tropical cirrus occurrence is important in predicting the role of these clouds on...

2

Testing a New Cirrus Cloud Parameterizaton  

NLE Websites -- All DOE Office Websites (Extended Search)

Testing a New Cirrus Cloud Parameterization Testing a New Cirrus Cloud Parameterization in NCAR CCM3 D. Zurovac-Jevtic, G. J. Zhang, and V. Ramanathan Center for Atmospheric Sciences Scripps 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 general circulation models (GCMs), their treatment is very crude. For example, in the National Center for Atmospheric Research (NCAR) Community Climate Model (CCM3), IWC is prescribed as a function of column-integrated water vapor and height (Hack 1998). The in situ observations in the tropics indicate that the cirrus IWC is an order of magnitude larger than what is prescribed in the model (McFarquhar and Heymsfield 1996). The comparison with the International

3

The Mesoscale Dynamics of Thin Tropical Tropopause Cirrus  

Science Conference Proceedings (OSTI)

Thin cirrus clouds in the tropical tropopause layer (TTL) are warmed through the absorption of infrared radiation. The response of the cloud and the surrounding atmosphere to this thermal forcing is investigated through linear theory and ...

Dale R. Durran; Tra Dinh; Marie Ammerman; Thomas Ackerman

2009-09-01T23:59:59.000Z

4

Surface Temperature Related Variations in Tropical Cirrus Cloud as Measured by SAGE II  

Science Conference Proceedings (OSTI)

Data from the Stratospheric Aerosol and Gas Experiment II (SAGE II) solar occultation satellite instrument have been used to study the properties of tropical cloud over the altitude range 10.5–18.5 km. By virtue of its limb viewing measurement ...

G. S. Kent; E. R. Williams; P-H. Wang; M. P. McCormick; K. M. Skeens

1995-11-01T23:59:59.000Z

5

Annual, Interannual, and Intraseasonal Variability of Tropical Tropopause Transition Layer Cirrus  

Science Conference Proceedings (OSTI)

Cloud fields based on the first three years of data from the Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) mission are used to investigate the relationship between cirrus within the tropical tropopause transition ...

Katrina S. Virts; John M. Wallace

2010-10-01T23:59:59.000Z

6

Tropical Tropopause Transition Layer Cirrus as Represented by CALIPSO Lidar Observations  

Science Conference Proceedings (OSTI)

The spatial and temporal variability of cirrus cloud fraction within the tropical tropopause transition layer (TTL) is investigated based on three years of data from the Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) ...

Katrina S. Virts; John M. Wallace; Qiang Fu; Thomas P. Ackerman

2010-10-01T23:59:59.000Z

7

Tropical anvil cirrus evolution from observations and numerical...  

NLE Websites -- All DOE Office Websites (Extended Search)

cirrus evolution from observations and numerical simulations Deng, Min University of Utah Mace, Gerald University of Utah Category: Modeling The tropical anvil cirrus formation...

8

LIRAD Observations of Tropical Cirrus Clouds in MCTEX. Part II: Optical Properties and Base Cooling in Dissipating Storm Anvil Clouds  

Science Conference Proceedings (OSTI)

During the Maritime Continent Thunderstorm Experiment (MCTEX), several decaying storm anvils were observed. The anvil clouds exhibited typical patterns of fallout and decay over a number of hours of observation. The anvil bases were initially ...

C. M. R. Platt; R. T. Austin; S. A. Young; A. J. Heymsfield

2002-11-01T23:59:59.000Z

9

Evolution of a Florida Cirrus Anvil  

Science Conference Proceedings (OSTI)

This paper presents a detailed study of a single thunderstorm anvil cirrus cloud measured on 21 July 2002 near southern Florida during the Cirrus Regional Study of Tropical Anvils and Cirrus Layers–Florida Area Cirrus Experiment (CRYSTAL-FACE). ...

T. J. Garrett; B. C. Navarro; C. H. Twohy; E. J. Jensen; D. G. Baumgardner; P. T. Bui; H. Gerber; R. L. Herman; A. J. Heymsfield; P. Lawson; P. Minnis; L. Nguyen; M. Poellot; S. K. Pope; F. P. J. Valero; E. M. Weinstock

2005-07-01T23:59:59.000Z

10

An Accurate Parameterization of the Solar Radiative Properties of Cirrus Clouds for Climate Models  

Science Conference Proceedings (OSTI)

An accurate parameterization of the solar radiative properties of cirrus clouds is developed based on improved light scattering calculations. Here 28 ice crystal size distributions from in situ aircraft observations in both tropical and ...

Qiang Fu

1996-09-01T23:59:59.000Z

11

Mesoscale and Microscale Structure of Cirrus Clouds: Three Case Studies  

Science Conference Proceedings (OSTI)

The structure and composition of three basic cirrus cloud types are examined through coordinated aircraft and ground-based polarization lidar and radar measurements. The cloud systems consist of a multilayered orographic cirrus, a 6-km deep ...

Kenneth Sassen; David O'C. Starr; Taneil Uttal

1989-02-01T23:59:59.000Z

12

Cirrus clouds in a global climate model with a statistical cirrus cloud scheme  

E-Print Network (OSTI)

supersaturation in mixed-phase clouds is the saturation vapor pressure weighted by the proportions of ice to be in the liquid phase for clouds warmer than -35ºC, and is assumed to be in the ice phase for cirrus clouds. The conversion of this detrained condensate from liquid phase into the ice phase in the mixed-phase clouds

Meskhidze, Nicholas

13

Posters Sensitivity of Cirrus Cloud Radiative  

NLE Websites -- All DOE Office Websites (Extended Search)

7 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 shapes and sizes of ice crystals. For instance, the cloud albedo may vary by a factor of two, depending on whether hexagonal columns or bullet rosette ice crystals are assumed for a given ice water path (IWP). This variance occurs primarily because, at sizes characteristic of cirrus

14

Detecting and Evaluating the Effect of Overlaying Thin Cirrus Cloud on MODIS Retrieved Water-Cloud Droplet Effective Radius  

NLE Websites -- All DOE Office Websites (Extended Search)

Detecting and Evaluating the Effect 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% and more than 70% in the tropics (Wylie et al. 1994). The probability of cirrus clouds overlaying a low-level boundary layer cloud system is greater than 50% (Hahn et al. 1982, 1984; Tian and Curry 1989; Mace et al. 1997). They are often optically thin and semitransparent and frequently reside in high altitude overlapping with a low-level

15

The Prospect for Remote Sensing of Cirrus Clouds with a Submillimeter-Wave Spectrometer  

Science Conference Proceedings (OSTI)

Given the substantial radiative effects of cirrus clouds and the need to validate cirrus cloud mass in climate models, it is important to measure the global distribution of cirrus properties with satellite remote sensing. Existing cirrus remote ...

K. Franklin Evans; Aaron H. Evans; Ira G. Nolt; B. Thomas Marshall

1999-05-01T23:59:59.000Z

16

Modeling of Submillimeter Passive Remote Sensing of Cirrus Clouds  

Science Conference Proceedings (OSTI)

The scattering properties of cirrus clouds at submillimeter-wave frequencies are analyzed and characterized in this paper. This study lays a theoretical foundation for using radiometric measurements to investigate and monitor cirrus properties ...

K. Franklin Evans; Steven J. Walter; Andrew J. Heymsfield; Merritt N. Deeter

1998-02-01T23:59:59.000Z

17

Cirrus Clouds. Part I: A Cirrus Cloud Model  

Science Conference Proceedings (OSTI)

A two-dimensional (x, z), time-dependent, numerical cloud model is developed for the purpose of investigating the role of various physical processes involved in the maintenance of cirriform clouds. In addition to accounting for dynamic and ...

David O'C. Starr; Stephen K. Cox

1985-12-01T23:59:59.000Z

18

Analysis of the Tropical Tropopause Layer Cirrus in CALIPSO and MLS Data - A Water Perspective  

E-Print Network (OSTI)

Two mechanisms appear to be primarily responsible for the formation of cirrus clouds in Tropical Tropopause Layer (TTL): detrainment from deep convective anvils and in situ initiation. Here we propose to identify TTL cirrus clouds by analyzing water content measurements from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) and Aura Microwave Limb Sounder (MLS). Using ice water content (IWC) and water vapor (H2O) abundances we identify TTL cirrus clouds that contain too much ice to have been formed in situ — and therefore must be of convective origin. We use two methods to infer amounts of water vapor available for in situ formation. Clouds with IWC greater than this threshold are categorized as being of convective origin; clouds with IWC below the threshold are ambiguous — they could either form from in situ or still be of convective origin. Applying the thresholds from December 2008 to November 2009, we found that at least 19.2% of tropical cirrus were definitively of convective origin at the tropopause (375 K) during boreal winter. At each level, we found three maxima in the occurrence of convective cirrus: western Pacific, equatorial Africa, and South America. Averaged over the entire tropics (30oS to 30oN), we found convective cirrus occurs more frequently in boreal winter and less frequently in boreal summer, basically following the a decreasing trend from DJF, MAM, SON, to JJA. During boreal summer, we found that only 4.6% of tropical cirrus come from convection. Sensitivity tests show that the thresholds derived at 390 K have the largest uncertainty. At lower levels, especially 375 K, our thresholds are robust.

Wang, Tao

2011-05-01T23:59:59.000Z

19

Association of Tropical Cirrus in the 10–15-km Layer with Deep Convective Sources: An Observational Study Combining Millimeter Radar Data and Satellite-Derived Trajectories  

Science Conference Proceedings (OSTI)

In this paper, millimeter cloud radar (MMCR) and Geosynchronous Meteorological Satellite (GMS) data are combined to study the properties of tropical cirrus that are common in the 10–15-km layer of the tropical troposphere in the western Pacific. ...

Gerald G. Mace; Min Deng; Brian Soden; Ed Zipser

2006-02-01T23:59:59.000Z

20

Four Years of Global Cirrus Cloud Statistics Using HIRS  

Science Conference Proceedings (OSTI)

Trends in global upper-tropospheric transmissive cirrus cloud cover are beginning to emerge from a four-year cloud climatology using NOAA polar-orbiting High-Resolution Infrared Radiation Sounder (HIRS) multispectral data. Cloud occurrence, ...

Donald P. Wylie; W. Paul Menzel; Harold M. Woolf; Kathleen I. Strabala

1994-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

A Characterization of Cirrus Cloud Properties That Affect Laser Propagation  

Science Conference Proceedings (OSTI)

Future high-altitude laser systems may be affected by cirrus clouds. Laser transmission models were applied to measured and retrieved cirrus properties to determine cirrus impact on power incident on a target or receiver. A major goal was to see ...

Donald C. Norquist; Paul R. Desrochers; Patrick J. McNicholl; John R. Roadcap

2008-05-01T23:59:59.000Z

22

Cirrus Cloud Properties from a Cloud-Resolving Model Simulation Compared to Cloud Radar Observations  

Science Conference Proceedings (OSTI)

Cloud radar data collected at the Atmospheric Radiation Measurement (ARM) Program's Southern Great Plains site were used to evaluate the properties of cirrus clouds that occurred in a cloud-resolving model (CRM) simulation of the 29-day summer ...

Yali Luo; Steven K. Krueger; Gerald G. Mace; Kuan-Man Xu

2003-02-01T23:59:59.000Z

23

A Comparison of Cirrus Cloud Visible Optical Depth Derived from Lidar  

NLE Websites -- All DOE Office Websites (Extended Search)

Comparison of Cirrus Cloud Visible Optical Depth Derived from Lidar Comparison of Cirrus Cloud Visible Optical Depth Derived from Lidar Lo, Chaomei Pacific Northwest National Laboratory Comstock, Jennifer Pacific Northwest National Laboratory Flynn, Connor Pacific Northwest National Laboratory Category: Cloud Properties Optically thin clouds (e.g. optical depth < 3) can have a significant impact on radiative heating in the atmosphere, particularly in the cold upper troposphere. Currently, there is no value-added product (VAP) in the Atmospheric Radiation Measurement (ARM) program archive that produces thin cloud optical depth, particularly at the Tropical Western Pacific and North Slope of Alaska sites. A VAP is under development to obtain the cirrus cloud visible optical depth from the MPLNOR (Micro Pulse Lidar Normalized

24

ARM - Publications: Science Team Meeting Documents: Cirrus Cloud...  

NLE Websites -- All DOE Office Websites (Extended Search)

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...

25

A Numerical Study of Cirrus Clouds. Part I: Model Description  

Science Conference Proceedings (OSTI)

This article, the first of a two-part series, presents a detailed description of a two-dimensional numerical cloud model directed toward elucidating the physical processes governing the evolution of cirrus clouds. The two primary scientific ...

Hui-Chun Liu; Pao K. Wang; Robert E. Schlesinger

2003-04-01T23:59:59.000Z

26

In Situ Observations of the Microphysical Properties of Wave, Cirrus, and Anvil Clouds. Part II: Cirrus Clouds  

Science Conference Proceedings (OSTI)

A Learjet research aircraft was used to collect microphysical data, including cloud particle imager (CPI) measurements of ice particle size and shape, in 22 midlatitude cirrus clouds. The dataset was collected while the aircraft flew 104 ...

R. Paul Lawson; Brad Baker; Bryan Pilson; Qixu Mo

2006-12-01T23:59:59.000Z

27

Time Correlations in Backscattering Radar Reflectivity Measurements from Cirrus Clouds  

NLE Websites -- All DOE Office Websites (Extended Search)

Time Correlations in Backscattering Radar Reflectivity Time Correlations in Backscattering Radar Reflectivity Measurements from Cirrus Clouds K. Ivanova, H. N. Shirer, and E. E. Clothiaux Pennsylvania State University University Park, Pennsylvania T. P. Ackerman Pacific Northwest National Laboratory Richland, Washington Introduction The state variables of the atmosphere exhibit correlations at various spatial and temporal scales. These correlations are crucial for understanding short- and long-term trends in climate. Cirrus clouds are important phenomena in the troposphere affecting climate. To improve future parameterization of cirrus clouds in climate models, we must understand the cloud properties and how they change within the cloud. We consider fluctuations of cloud radar signals obtained at isodepths within cirrus clouds

28

Crystal-Face Archive of Images: Images from the Cirrus Regional Study of Tropical Anvils and Cirrus Layers - Florida Area Cirrus Experiment  

DOE Data Explorer (OSTI)

The Cirrus Regional Study of Tropical Anvils and Cirrus Layers - Florida Area Cirrus Experiment (CRYSTAL-FACE) took place in the summer of 2002 over Key West, Florida. It was a measurement campaign that investigated the physical properties and formation processes of tropical cirrus clouds. Six aircraft with various instruments flew missions, gathering data that were compared with ground-based instrument data and that would be used in the modeling of the EarthÆs climate. DOE was only one of several federal agencies involved, along with various universities and science institutes. The Crystal-Face numeric data sets are available in DOEÆs ARM Archive at http://www.archive.arm.gov/armlogin/login.jsp and in NASAÆs ARCS archive at http://espoarchive.nasa.gov/archive/arcs/crystalf/images/npol_1/. Various sets of data are also available at some of the participating universities. The official home page for Crystal-Face is http://www.espo.nasa.gov/crystalface/index.html. See the 52 science posters at http://www.espo.nasa.gov/crystalface/posters.html

29

Crystal-Face Science Posters - Post-mission Science Posters from the Cirrus Regional Study of Tropical Anvils and Cirrus Layers  

DOE Data Explorer (OSTI)

The Cirrus Regional Study of Tropical Anvils and Cirrus Layers - Florida Area Cirrus Experiment (CRYSTAL-FACE) took place in the summer of 2002 over Key West, Florida. It was a measurement campaign that investigated the physical properties and formation processes of tropical cirrus clouds. Six aircraft with various instruments flew missions, gathering data that were compared with ground-based instrument data and that would be used in the modeling of the Earth's climate. DOE was only one of several federal agencies involved, along with various universities and science institutes. The Crystal-Face numeric data sets are available in DOE's ARM Archive at http://www.archive.arm.gov/armlogin/login.jsp and in NASA's ARCS archive at http://espoarchive.nasa.gov/archive/arcs/crystalf/images/npol_1/. Various sets of data are also available at some of the participating universities. The official home page for Crystal-Face is http://www.espo.nasa.gov/crystalface/index.html.

30

Remote sensing of cirrus cloud particle size and optical depth using polarimetric sensor measurements  

E-Print Network (OSTI)

and J. Pelon, 1999b: Remote sensing of cirrus radiativepar- ticles: Remote sensing and climatic implications.S. C. Tsay, 1999: Remote sensing of cirrus cloud parameters

Ou, Szu-cheng C; Liou, K N; Takano, Y; Slonaker, R L

2005-01-01T23:59:59.000Z

31

Clouds in Tropical Cyclones  

Science Conference Proceedings (OSTI)

Clouds within the inner regions of tropical cyclones are unlike those anywhere else in the atmosphere. Convective clouds contributing to cyclogenesis have rotational and deep intense updrafts but tend to have relatively weak downdrafts. Within ...

Robert A. Houze Jr.

2010-02-01T23:59:59.000Z

32

Clouds in Tropical Cyclones  

Science Conference Proceedings (OSTI)

Clouds within the inner regions of tropical cyclones are unlike those anywhere else in the atmosphere. Convective clouds contributing to cyclogenesis have rotational and deep intense updrafts but tend to have relatively weak downdrafts. Within the ...

Robert A. Houze Jr.

2010-02-01T23:59:59.000Z

33

Relating Cirrus Cloud Properties to Observed Fluxes: A Critical Assessment  

Science Conference Proceedings (OSTI)

The accuracy needed in cirrus cloud scattering and microphysical properties is quantified such that the radiative effect on climate can he determined. Our ability to compute and observe these properties to within needed accuracies is assessed, ...

A. M. Vogelmann; T. P. Ackerman

1995-12-01T23:59:59.000Z

34

Radiative Properties of Cirrus Clouds in the Infrared Region  

Science Conference Proceedings (OSTI)

A multiple-scattering radiative transfer model is employed to evaluate the 11 ?m and the broad-band infrared (IR) fluxes, cooling rates and emittances in model cirrus clouds for a number of standard vertical atmospheric profiles of temperature ...

Graeme L. Stephens

1980-02-01T23:59:59.000Z

35

Supersaturation Fluctuations in Cirrus Clouds Driven by Colored Noise  

Science Conference Proceedings (OSTI)

Fundamental properties of ice supersaturation variability in cirrus clouds are studied by means of an idealized probabilistic model. Damped supersaturation fluctuations are assumed to be exponentially correlated in time, statistically stationary, ...

B. Kärcher

2012-02-01T23:59:59.000Z

36

Radiative Properties of Cirrus Clouds Derived from Surface Interferometric Measurements  

Science Conference Proceedings (OSTI)

Beam transmittance, emittance, reflectance, and outgoing radiance are inferred from interferometric measurements in the infrared window region for 14 temperate continental and 12 subtropical cirrus cloud cash observed during FIRE II at Parsons, ...

Gordon H. Beck; John M. Davis; S. K. Cox

1996-08-01T23:59:59.000Z

37

On the Transition of Contrails into Cirrus Clouds  

Science Conference Proceedings (OSTI)

In situ observations of the microphysical properties of upper-tropospheric contrails and cirrus clouds have been performed during more than 15 airborne missions over central Europe. Experimental and technical aspects concerning in situ ...

F. Schröder; B. Kärcher; C. Duroure; J. Ström; A. Petzold; J.-F. Gayet; B. Strauss; P. Wendling; S. Borrmann

2000-02-01T23:59:59.000Z

38

In Situ Observations of Cirrus Cloud Microphysical Properties Using the Counterflow Virtual Impactor  

Science Conference Proceedings (OSTI)

This study presents a new technique for making in situ measurements of cirrus cloud microphysical properties. Sampling of cirrus clouds was performed using a counterflow virtual impactor (CVI). The CVI was used to sample cloud elements larger ...

K. B. Noone; K. J. Noone; J. Heintzenberg; J. Ström; J. A. Ogren

1993-06-01T23:59:59.000Z

39

A Methodology for Measuring Cirrus Cloud Visible-to-Infrared Spectral Optical Depth Ratios  

Science Conference Proceedings (OSTI)

Knowledge of cirrus cloud optical depths is necessary to understand the earth’s current climate and to model the cloud radiation impact on future climate. Cirrus clouds, depending on the ratio of their shortwave “visible” to longwave “infrared” ...

Daniel H. DeSlover; William L. Smith; Paivi K. Piironen; Edwin W. Eloranta

1999-02-01T23:59:59.000Z

40

A Summary of the Physical Properties of Cirrus Clouds  

Science Conference Proceedings (OSTI)

A review of existing literature is made to determine typical values for the physical properties cirrus clouds. The properties examined (with typical values and measured ranges) are cloud-center altitude (9 km, 4 to 20 km), cloud thickness (1.5 km,...

David R. Dowling; Lawrence F. Radke

1990-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Simulations of cirrus clouds using an explicit cloud model: integrating ARM  

NLE Websites -- All DOE Office Websites (Extended Search)

Simulations of cirrus clouds using an explicit cloud model: integrating ARM Simulations of cirrus clouds using an explicit cloud model: integrating ARM water vapor and forcing data for analysis of cirrus formation and evolution Comstock, Jennifer Pacific Northwest National Laboratory Lin, Ruei-Fong NASA/Goddard Space Flight Center Starr, David NASA/Goddard Space Flight Center Yang, Ping Texas A&M Category: Modeling Understanding the atmospheric conditions required to initiate cirrus formation and produce observed microphysical properties is crucial to improving the representation of cirrus clouds in climate models. Ice formation in cirrus generally occurs at cold temperatures (below -30 ï‚°C) and can take the form of either homogeneous or heterogeneous nucleation. The ice supersaturation required for ice formation is smaller for

42

Microphysical and Dynamical Influences on Cirrus Cloud Optical Depth Distributions  

SciTech Connect

Cirrus cloud inhomogeneity occurs at scales greater than the cirrus radiative smoothing scale ({approx}100 m), but less than typical global climate model (GCM) resolutions ({approx}300 km). Therefore, calculating cirrus radiative impacts in GCMs requires an optical depth distribution parameterization. Radiative transfer calculations are sensitive to optical depth distribution assumptions (Fu et al. 2000; Carlin et al. 2002). Using raman lidar observations, we quantify cirrus timescales and optical depth distributions at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site in Lamont, OK (USA). We demonstrate the sensitivity of outgoing longwave radiation (OLR) calculations to assumed optical depth distributions and to the temporal resolution of optical depth measurements. Recent work has highlighted the importance of dynamics and nucleation for cirrus evolution (Haag and Karcher 2004; Karcher and Strom 2003). We need to understand the main controls on cirrus optical depth distributions to incorporate cirrus variability into model radiative transfer calculations. With an explicit ice microphysics parcel model, we aim to understand the influence of ice nucleation mechanism and imposed dynamics on cirrus optical depth distributions.

Kay, J.; Baker, M.; Hegg, D.

2005-03-18T23:59:59.000Z

43

The 27–28 October 1986 FIRE IFO Cirrus Case Study: Cloud Microstructure  

Science Conference Proceedings (OSTI)

The temperature and windfield structure and hydrometeor composition of cirrus clouds sampled by the NCAR King Air and Sabreliner aircraft on 28 October 1986 near Madison, Wisconsin are described as part of a case study that examines cirrus cloud ...

Andrew J. Heymsfield; Karen M. Miller; James D. Spinhirne

1990-11-01T23:59:59.000Z

44

Influence of Cirrus Clouds on Weather and Climate Processes: A Global Perspective  

Science Conference Proceedings (OSTI)

Current understanding and knowledge of the composition and structure of cirrus clouds are reviewed and documented in this paper. In addition, the radiative properties of cirrus clouds as they relate to weather and climate processes are described ...

Kuo-Nan Liou

1986-06-01T23:59:59.000Z

45

A Cirrus-Cloud Experiment: Intensive Field Observations Planned for Fire  

Science Conference Proceedings (OSTI)

Plans for an intensive cirrus-cloud field experiment are described. The Cirrus Intensive Field Observations (Citrus IFO) is a major component of the First ISCCP (International Satellite Cloud Climatology Project) Regional Experiment (FIRE). The ...

David O'C. Starr

1987-02-01T23:59:59.000Z

46

Radiative Heating Profiles in Simple Cirrus Cloud Systems  

Science Conference Proceedings (OSTI)

Results from one-dimensional cirrus cloud model simulations in the absence of upward velocities are used to show that the growth/sublimation of the ice particles in the cloud, and the fact that they are falling, can be important factors in ...

Andrew Detwiler; V. Ramaswamy

1990-09-01T23:59:59.000Z

47

Cirrus Cloud Ice Water Content Radar Algorithm Evaluation Using an Explicit Cloud Microphysical Model  

Science Conference Proceedings (OSTI)

A series of cirrus cloud simulations performed using a model with explicit cloud microphysics is applied to testing ice water content retrieval algorithms based on millimeter-wave radar reflectivity measurements. The simulated ice particle size ...

Kenneth Sassen; Zhien Wang; Vitaly I. Khvorostyanov; Graeme L. Stephens; Angela Bennedetti

2002-06-01T23:59:59.000Z

48

Radiative Transfer in Cirrus Clouds. Part IV: On Cloud Geometry, Inhomogeneity, and Absorption  

Science Conference Proceedings (OSTI)

The effects of cloud geometry and inhomogeneity on the radiative properties of cirrus clouds are investigated by using the successive orders of scattering (SOS) approach for radiative transfer. This approach is an integral solution method that em ...

K. N. Liou; N. Rao

1996-11-01T23:59:59.000Z

49

Sensitivity Analysis of Cirrus Cloud Properties from High-Resolution Infrared Spectra. Part I: Methodology and Synthetic Cirrus  

Science Conference Proceedings (OSTI)

A set of simulated high-resolution infrared (IR) emission spectra of synthetic cirrus clouds is used to perform a sensitivity analysis of top-of-atmosphere (TOA) radiance to cloud parameters. Principal component analysis (PCA) is applied to ...

Brian H. Kahn; Annmarie Eldering; Michael Ghil; Simona Bordoni; Shepard A. Clough

2004-12-01T23:59:59.000Z

50

Cirrus Cloud Radiative and Microphysical Properties from Ground Observations and In Situ Measurements during FIRE 1991 and Their Application to Exhibit Problems in Cirrus Solar Radiative Transfer Modeling  

Science Conference Proceedings (OSTI)

Measurements from the FIRE 1991 cirrus cloud field experiment in the central United States are presented and analyzed.

S. Kinne; T. P. Ackerman; M. Shiobara; A. Uchiyama; A. J. Heymsfield; L. Miloshevich; J. Wendell; E. Eloranta; C. Purgold; R. W. Bergstrom

1997-09-01T23:59:59.000Z

51

Comparison of Methods to Determine Tropical Tropopause Layer Cirrus Formation Mechanisms  

SciTech Connect

A new method of estimating Tropical Tropopause Layer Cirrus (TTLC) formation mechanism (object method) is compared to interpretations of formation from previous studies using back trajectory calculations matched to convection identified from satellites and statistical relationships of TTLC with temperature and water vapor. The object method groups neighboring Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) TTLC cloud profiles into cloud objects and classifies them as convective (35% of TTLC) if they are directly attached to a convective cloud along the CALIPSO track. The percentage of back trajectory calculations that intersect convection (39-95% of TTLC within 5 days) depends strongly on the spatial and temporal resolution of the convection data set, and the manner in which deep convection is identified. Using minimum brightness temperature in 3 hourly, 1{sup o} resolution grid boxes to define convection, 46% of non-convective TTLC (37% of all TTLC) did not trace back to convection within 24 h. Back trajectory calculations of thin cirrus identified by the High Resolution Dynamics Limb Sounder (HIRDLS) gave similar results. Temperature is not a good proxy for formation mechanism as convective and non-convective TTLC frequencies both increase monotonically with decreasing temperature at approximately the same rate. Non-convective TTLC frequencies have a stronger relationship with relative humidity than convective TTLC frequencies, though are not sufficiently different to distinguish object method categories. A decrease in TTL cirrus frequency found at low temperatures in previous studies is caused by insufficient variability in reanalysis temperature data and is not indicative of TTLC formation mechanism.

Riihimaki, Laura D.; McFarlane, Sally A.; Liang, Calvin; Massie, Steven T.; Beagley, Nathaniel; Toth, Travis D.

2012-03-30T23:59:59.000Z

52

Cirrus Clouds and the Large-Scale Atmospheric State: Relationships Revealed by Six Years of Ground-Based Data  

Science Conference Proceedings (OSTI)

The properties of cirrus clouds observed at the Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) in Oklahoma are documented from a nearly continuous 6-yr record of 35-GHz cloud radar data. Cirrus frequency over the ACRF is ...

Gerald G. Mace; Sally Benson; Erik Vernon

2006-07-01T23:59:59.000Z

53

Cirrus Microphysics and Radiative Transfer: Cloud Field Study on 28 October 1986  

Science Conference Proceedings (OSTI)

Cloud data acquired during the cirrus intensive field operation of FIRE 86 are analyzed for a 75 × 50-km2 cirrus cloud field that passed over Wausau, Wisconsin, during the morning of 28 October 1986. Remote-sensing measurements from the ...

Stefan Kinne; Thomas P. Ackerman; Andrew J. Heymsfield; Francisco P. J. Valero; Kenneth Sassen; James D. Spinhirne

1992-05-01T23:59:59.000Z

54

Dynamical Characteristics of Cirrus Clouds from Aircraft and Radar Observations in Micro and Meso-? Scales  

Science Conference Proceedings (OSTI)

Cirrus clouds that formed on 26 November and 6 December 1991 during the First International Satellite Cloud Climatology Project Regional Experiment (FIRE) II, which took place over the Kansas region. are studied because of significant dynamic ...

I. Gultepe; D. O'C. Starr; A. J. Heymsfield; T. Uttal; T. P. Ackerman; D. L. WestPhal

1995-12-01T23:59:59.000Z

55

Parameterization and Impact of Ice initiation Processes Relevant to Numerical Model Simulations of Cirrus Clouds  

Science Conference Proceedings (OSTI)

An effort to improve descriptions of ice initiation processes of relevance to cirrus clouds for use in regional-scale numerical cloud models with bulk microphysical schemes is described. This is approached by deriving practical parameterizations ...

Paul J. DeMott; Michael P. Meyers; William R. Cotton

1994-01-01T23:59:59.000Z

56

The Composite Characteristics of Cirrus Clouds: Bulk Properties Revealed by One Year of Continuous Cloud Radar Data  

Science Conference Proceedings (OSTI)

The properties of midlatitude cirrus clouds are examined using one year of continuous vertically pointing millimeter-wave cloud radar data collected at the Atmospheric Radiation Measurement Program Southern Great Plains site in Oklahoma. The goal ...

Gerald G. Mace; Eugene E. Clothiaux; Thomas P. Ackerman

2001-05-01T23:59:59.000Z

57

The Tropical Warm Pool International Cloud Experiment  

Science Conference Proceedings (OSTI)

A comprehensive dataset describing tropical cloud systems and their environmental setting and impacts has been collected during the Tropical Warm Pool International Cloud Experiment (TWP-ICE) and Aerosol and Chemical Transport in Tropical ...

Peter T. May; James H. Mather; Geraint Vaughan; Keith N. Bower; Christian Jakob; Greg M. McFarquhar; Gerald G. Mace

2008-05-01T23:59:59.000Z

58

Radiation Parameterization for Three-Dimensional Inhomogeneous Cirrus Clouds Applied to ARM Data and Climate Models  

DOE Green Energy (OSTI)

OAK-B135 (a) We developed a 3D radiative transfer model to simulate the transfer of solar and thermal infrared radiation in inhomogeneous cirrus clouds. The model utilized a diffusion approximation approach (four-term expansion in the intensity) employing Cartesian coordinates. The required single-scattering parameters, including the extinction coefficient, single-scattering albedo, and asymmetry factor, for input to the model, were parameterized in terms of the ice water content and mean effective ice crystal size. The incorporation of gaseous absorption in multiple scattering atmospheres was accomplished by means of the correlated k-distribution approach. In addition, the strong forward diffraction nature in the phase function was accounted for in each predivided spatial grid based on a delta-function adjustment. The radiation parameterization developed herein is applied to potential cloud configurations generated from GCMs to investigate broken clouds and cloud-overlapping effects on the domain-averaged heating rate. Cloud inhomogeneity plays an important role in the determination of flux and heating rate distributions. Clouds with maximum overlap tend to produce less heating than those with random overlap. Broken clouds show more solar heating as well as more IR cooling as compared to a continuous cloud field (Gu and Liou, 2001). (b) We incorporated a contemporary radiation parameterization scheme in the UCLA atmospheric GCM in collaboration with the UCLA GCM group. In conjunction with the cloud/radiation process studies, we developed a physically-based cloud cover formation scheme in association with radiation calculations. The model clouds were first vertically grouped in terms of low, middle, and high types. Maximum overlap was then used for each cloud type, followed by random overlap among the three cloud types. Fu and Liou's 1D radiation code with modification was subsequently employed for pixel-by-pixel radiation calculations in the UCLA GCM. We showed that the simulated cloud cover and OLR fields without special tuning are comparable to those of ISCCP dataset and the results derived from radiation budget experiments. Use of the new radiation and cloud schemes enhances the radiative warming in the middle to upper tropical troposphere and alleviates the cold bias in the UCLA atmospheric GCM. We also illustrated that ice crystal size and cloud inhomogeneous are significant factors affecting the radiation budgets at the top of the atmosphere and the surface (Gu et al. 2003). (c) An innovative approach has been developed to construct a 3D field of inhomogeneous clouds in general and cirrus in particular in terms of liquid/ice water content and particle size on the basis of a unification of satellite and ground-based cloud radar data. Satellite remote sensing employing the current narrow-band spectro-radiometers has limitation and only the vertically integrated cloud parameters (optical depth and mean particle size) can be determined. However, by combining the horizontal cloud mapping inferred from satellites with the vertical structure derived from the profiling Doppler cloud radar, a 3D cloud field can be constructed. This represents a new conceptual approach to 3D remote sensing and imaging and offers a new perspective in observing the cloud structure. We applied this novel technique to AVHRR/NOAA satellite and mm-wave cloud radar data obtained from the ARM achieve and assessed the 3D cirrus cloud field with the ice crystal size distributions independently derived from optical probe measurements aboard the University of North Dakota Citation. The retrieved 3D ice water content and mean effective ice crystal size involving an impressive cirrus cloud occurring on April 18, 1997, are shown to be comparable to those derived from the analysis of collocated and coincident in situ aircraft measurements (Liou et al. 2002). (d) Detection of thin cirrus with optical depths less than 0.5, particularly those occurring i n the tropics remains a fundamental problem in remote sensing. We developed a new detection scheme for the

Kuo-Nan Liou

2003-12-29T23:59:59.000Z

59

The Dependence of Cirrus Cloud-Property Retrievals on Size-Distribution  

NLE Websites -- All DOE Office Websites (Extended Search)

The Dependence of Cirrus Cloud-Property Retrievals on Size-Distribution The Dependence of Cirrus Cloud-Property Retrievals on Size-Distribution Shape d'Entremont, Robert Atmospheric and Environmental Research, Inc. Mitchell, David Desert Research Institute Category: Cloud Properties Our project has focused on using satellite- and ground-based passive thermal infrared radiance observations to retrieve cirrus cloud properties, most importantly ice water path (IWP), effective particle size (Deff), and visible extinction optical thickness (tau). During this past year we began comparing our cirrus retrieval results with aircraft observations at the ARM CART site, and we are participating in a summary intercomparison study with other retrieval algorithms as a member of the high-clouds working group. Our passive-infrared retrieval scheme, based on different wavelength

60

Remote Sensing of Cirrus Cloud Particle Size and Optical Depth Using Polarimetric Sensor Measurements  

Science Conference Proceedings (OSTI)

This paper presents a conceptual approach toward the remote sensing of cirrus cloud particle size and optical depth using the degree of polarization and polarized reflectance associated with the first three Stokes parameters, I, Q, and U, for the ...

S. C. Ou; K. N. Liou; Y. Takano; R. L. Slonaker

2005-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

The Remote Sensing of Thin Cirrus Cloud Using Satellites, Lidar and Radiative Transfer Theory  

Science Conference Proceedings (OSTI)

The problem of retrieving cirrus cloud optical depth from radiance measurements made by instruments aboard operational meteorological satellites is addressed. A method is proposed that exploits the relationship between observed differences in the ...

Robert S. Stone; Graeme L. Stephens; C. M. R. Platt; S. Banks

1990-05-01T23:59:59.000Z

62

A New Parameterization of an Asymmetry Factor of Cirrus Clouds for Climate Models  

Science Conference Proceedings (OSTI)

The aspect ratio (AR) of a nonspherical ice particle is identified as the key microphysical parameter to determine its asymmetry factor for solar radiation. The mean effective AR is defined for cirrus clouds containing various nonspherical ice ...

Qiang Fu

2007-11-01T23:59:59.000Z

63

Retrieval of Vertical Profiles of Cirrus Cloud Microphysical Parameters from Doppler Radar and Infrared Radiometer Measurements  

Science Conference Proceedings (OSTI)

This paper describes a new method to retrieve vertical profiles of the parameters of cirrus cloud microphysics that are important for the estimation of climatic feedback. These parameters are the particle characteristic size and ice mass content. ...

S. Y. Matrosov; B. W. Orr; R. A. Kropfli; J. B. Snider

1994-05-01T23:59:59.000Z

64

Determination of Semi-Transparent Cirrus Cloud Temperature from Infrared Radiances: Application to METEOSAT  

Science Conference Proceedings (OSTI)

The use of simultaneous infrared measurements to derive the temperature and emissivity of semi-transparent cirrus clouds is experimentally investigated. Results from the NASA/CONVAIR-990 Winter Experiment Program, 1977 (WEP) are discussed. It is ...

Gerard Szejwach

1982-03-01T23:59:59.000Z

65

The Impact of Ice Crystal Shapes, Size Distributions, and Spatial Structures of Cirrus Clouds on Solar Radiative Fluxes  

Science Conference Proceedings (OSTI)

The solar radiative properties of cirrus clouds depend on ice particle shape, size, and orientation, as well as on the spatial cloud structure. Radiation schemes in atmospheric circulation models rely on estimates of cloud optical thickness only. ...

I. Schlimme; A. Macke; J. Reichardt

2005-07-01T23:59:59.000Z

66

Observations of temperature, wind, cirrus, and trace gases in the tropical tropopause transition layer during the MJO  

Science Conference Proceedings (OSTI)

Satellite observations of temperature, optically thin cirrus clouds, and trace gases derived from the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC), Cloud-Aerosol Lidar and Infrared Pathfinder Satellite ...

Katrina S. Virts; John M. Wallace

67

Sensitivity Studies of Dust Ice Nuclei Effect on Cirrus Clouds with the Community Atmosphere Model CAM5  

SciTech Connect

In this study the effect of dust aerosol on upper tropospheric cirrus clouds through heterogeneous ice nucleation is investigated in the Community Atmospheric Model version 5 (CAM5) with two ice nucleation parameterizations. Both parameterizations consider homogeneous and heterogeneous nucleation and the competition between the two mechanisms in cirrus clouds, but differ significantly in the number concentration of heterogeneous ice nuclei (IN) from dust. Heterogeneous nucleation on dust aerosol reduces the occurrence frequency of homogeneous nucleation and thus the ice crystal number concentration in the Northern Hemisphere (NH) cirrus clouds compared to simulations with pure homogeneous nucleation. Global and annual mean shortwave and longwave cloud forcing are reduced by up to 2.0 ± 0.1 W m?2 (1? uncertainty) and 2.4 ± 0.1 W m?2, respectively due to the presence of dust IN, with the net cloud forcing change of ?0.40 ± 0.20 W m?2. Comparison of model simulations with in situ aircraft data obtained in NH mid-latitudes suggests that homogeneous ice nucleation may play an important role in the ice nucleation at these regions with temperatures of 205–230 K. However, simulations overestimate observed ice crystal number concentrations in the tropical tropopause regions with temperatures of 190–205 K, and overestimate the frequency of occurrence of high ice crystal number concentration (> 200 L?1) and underestimate the frequency of low ice crystal number concentration (< 30 L?1) at NH mid-latitudes. These results highlight the importance of quantifying the number concentrations and properties of heterogeneous IN (including dust aerosol) in the upper troposphere from the global perspective.

Liu, Xiaohong; Shi, Xiangjun; Zhang, Kai; Jensen, Eric; Gettelman, A.; Barahona, Donifan; Nenes, Athanasios; Lawson, Paul

2012-12-19T23:59:59.000Z

68

Observed and Simulated Cirrus Cloud Properties at the SGP CART Site  

NLE Websites -- All DOE Office Websites (Extended Search)

and Simulated Cirrus Cloud Properties and Simulated Cirrus Cloud Properties at the SGP CART Site A. D. Del Genio and A. B. Wolf National Aeronautics and Space Administration Goddard Institute for Space Studies New York, New York G. G. Mace University of Utah Salt Lake City, Utah Introduction Despite their potential importance in a long-term climate change, less is known about cirrus clouds than most other cloud types, for a variety of reasons (Del Genio 2001) including: (1) the difficulty of remotely sensing ice water content (IWC), (2) uncertainty in the identities of ice nuclei and the relative importance of different nucleation processes, (3) significant variations in depth and optical thickness caused by formation and sedimentation of large particles, and (4) our relatively poor documentation of

69

Cirrus Cloud Properties and the Large-Scale Meteorological Environment: Relationships Derived from A-Train and NCEP–NCAR Reanalysis Data  

Science Conference Proceedings (OSTI)

Empirical knowledge of how cirrus cloud properties are coupled with the large-scale meteorological environment is a prerequisite for understanding the role of microphysical processes in the life cycle of cirrus cloud systems. Using active and ...

Elizabeth Berry; Gerald G. Mace

2013-05-01T23:59:59.000Z

70

Oscillation of High-Level Cirrus and Heavy Precipitation around Australian Region Tropical Cyclones  

Science Conference Proceedings (OSTI)

A study of 27 days of three-hourly GMS infrared data for 11 tropical cyclones in the Australian region has revealed that the area of the cirrus canopy executes a marked diurnal oscillation with maximum at +3 h of 0800 LMST Mean Solar Time (LMST) ...

F. A. Lajoie; I. J. Butterworth

1984-03-01T23:59:59.000Z

71

The 27–28 October 1986 FIRE IFO Cirrus Case Study: A Five Lidar Overview of Cloud Structure and Evolution  

Science Conference Proceedings (OSTI)

Optical remote sensing measurements of cirrus cloud properties were collected by one airborne and four ground-based lidar systems over a 32-h period during this cue study from the First ISCCP (International Satellite Cloud Climatology Program) ...

Kenneth Sassen; Christian J. Grund; James D. Spinhirne; Michael M. Hardesty; Jose M. Alvarez

1990-11-01T23:59:59.000Z

72

Relative Humidity and Temperature Influences on Cirrus Formation and Evolution: Observations from Wave Clouds and FIRE II  

Science Conference Proceedings (OSTI)

Measurements in orographic wave clouds. and in cirrus sampled during FIRE II, are used to investigate ice nucleation in the upper troposphere. The dynamically and microphysically simpler quasi-steady-state wave clouds provide relatively ideal ...

Andrew J. Heymsfield; Larry M. Miloshevich

1995-12-01T23:59:59.000Z

73

Improved Detection of Optically Thin Cirrus Clouds in Nighttime Multispectral Meteorological Satellite Imagery Using Total Integrated Water Vapor Information  

Science Conference Proceedings (OSTI)

The accurate identification of optically thin cirrus clouds in global meteorological satellite imagery by automated cloud analysis algorithms is critical to environmental remote sensing studies, such as those related to climate change. While ...

Keith D. Hutchison; Kenneth R. Hardy; Bo-Cai Gao

1995-05-01T23:59:59.000Z

74

Tropical Cloud Life Cycle and Overlap Structure  

NLE Websites -- All DOE Office Websites (Extended Search)

Tropical Cloud Life Cycle and Overlap Structure Vogelmann, Andrew Brookhaven National Laboratory Jensen, Michael Brookhaven National Laboratory Kollias, Pavlos Brookhaven National...

75

Tropical Thermostats and Low Cloud Cover  

Science Conference Proceedings (OSTI)

The ability of subtropical stratus low cloud cover to moderate or amplify the tropical response to climate forcing such as increased CO2 is considered. Cloud radiative forcing over the subtropics is parameterized using an empirical relation ...

R. L. Miller

1997-03-01T23:59:59.000Z

76

Analysis of Aircraft, Radiosonde, and Radar Observations in Cirrus Clouds Observed during FIRE II: The Interactions between Environmental Structure, Turbulence, and Cloud Microphysical Properties  

Science Conference Proceedings (OSTI)

Ways to determine the turbulence intensity and the horizontal variability in cirrus clouds have been investigated using First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment II aircraft, radiosonde, and radar data. ...

Samantha A. Smith; Anthony D. DelGenio

2001-03-01T23:59:59.000Z

77

Evaluate the Effect of Upper-Level Cirrus Clouds on Satellite Retrievals of Low-Level Cloud Droplet Effective Radius  

NLE Websites -- All DOE Office Websites (Extended Search)

the Effect of Upper-Level Cirrus Clouds 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 absorbed by the earth system. An estimate of reducing the global-mean droplet effective radius (r e ) of these low-level clouds by ~2 µm, while keeping the column liquid water constant would balance the warming due to CO 2 doubling in the atmosphere (Slingo 1990). Accurate determination of the droplet r

78

Measurements of the Total Water Content of Cirrus Clouds. Part II: Instrument Performance and Validation  

Science Conference Proceedings (OSTI)

This paper describes the performance and in-flight validation of an instrument mounted in a pallet on the NASA WB-57 research aircraft that measures the sum of gas phase and solid phase water, or total water, in cirrus clouds. Using a heated ...

E. M. Weinstock; J. B. Smith; D. Sayres; J. V. Pittman; N. Allen; J. G. Anderson

2006-11-01T23:59:59.000Z

79

Measurements of the Total Water Content of Cirrus Clouds. Part I: Instrument Details and Calibration  

Science Conference Proceedings (OSTI)

This paper describes an instrument designed to measure the sum of gas phase and solid phase water, or total water, in cirrus clouds, and to be mounted in a pallet in the underbelly of the NASA WB-57 research aircraft. The ice water content of ...

E. M. Weinstock; J. B. Smith; D. Sayres; J. R. Spackman; J. V. Pittman; N. Allen; J. Demusz; M. Greenberg; M. Rivero; L. Solomon; J. G. Anderson

2006-11-01T23:59:59.000Z

80

The Properties and Formation of Cirrus Clouds over the Tibetan Plateau Based on Summertime Lidar Measurements  

Science Conference Proceedings (OSTI)

As part of the Tibet Ozone, Aerosol and Radiation (TOAR) project, a micropulse lidar was operated in Naqu (31.5°N, 92.1°E; 4508 m MSL) on the Tibetan Plateau to observe cirrus clouds continuously from 19 July to 26 August 2011. During the ...

Q. S. He; C. C. Li; J. Z. Ma; H. Q. Wang; G. M. Shi; Z. R. Liang; Q. Luan; F. H. Geng; X. W. Zhou

2013-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Modeling Cirrus Clouds. Part I: Treatment of Bimodal Size Spectra and Case Study Analysis  

Science Conference Proceedings (OSTI)

A model has been developed that predicts the evolution of bimodal size spectra in cirrus clouds. This was done by predicting two size distributions: one for ice particles less than about 150 µm and another for larger particles. The sum of these ...

David L. Mitchell; Steven K. Chai; Yangang Liu; Andrew J. Heymsfield; Yayi Dong

1996-10-01T23:59:59.000Z

82

Phenomenological Description of Tropical Clouds Using CloudSat Cloud Classification  

Science Conference Proceedings (OSTI)

Two years of tropical oceanic cloud observations are analyzed using the operational CloudSat cloud classification product and Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) lidar. Relationships are examined between ...

Ali Behrangi; Terry Kubar; Bjorn Lambrigtsen

2012-10-01T23:59:59.000Z

83

Midlatitude Cirrus Clouds Derived from Hurricane Nora: A Case Study with Implications for Ice Crystal Nucleation and Shape  

Science Conference Proceedings (OSTI)

Hurricane Nora traveled up the Baja Peninsula coast in the unusually warm El Niño waters of September 1997 until rapidly decaying as it approached southern California on 24 September. The anvil cirrus blowoff from the final surge of tropical ...

Kenneth Sassen; W. Patrick Arnott; David O'C. Starr; Gerald G. Mace; Zhien Wang; Michael R. Poellot

2003-04-01T23:59:59.000Z

84

The Role of Ice Particle Shapes and Size Distributions in the Single Scattering Properties of Cirrus Clouds  

Science Conference Proceedings (OSTI)

The roles of ice particle size distributions (SDs) and particle shapes in cirrus cloud solar radiative transfer are investigated by analyzing SDs obtained from optical array probe measurements (particle sizes larger than 20–40 ?m) during ...

Andreas Macke; Peter N. Francis; Greg M. McFarquhar; Stefan Kinne

1998-09-01T23:59:59.000Z

85

Information Content of AVHRR Channels 4 and 5 with Respect to the Effective Radius of Cirrus Cloud Particles  

Science Conference Proceedings (OSTI)

This paper investigates the important difference in the relationship between brightness temperatures between the 11-?m and the 12-?n AVHRR data and the microphysical properties of the semitransparent cirrus clouds. In the nonscattering ...

F. Parol; J. C. Buriez; G. Brogniez; Y. Fouquart

1991-07-01T23:59:59.000Z

86

A Midlatitude Cirrus Cloud Climatology from the Facility for Atmospheric Remote Sensing. Part II: Microphysical Properties Derived from Lidar Depolarization  

Science Conference Proceedings (OSTI)

In Part II of this series of papers describing the results of the extended time observations of cirrus clouds from the University of Utah Facility for Atmospheric Remote Sensing (FARS), the information content of laser backscatter depolarization ...

Kenneth Sassen; Sally Benson

2001-08-01T23:59:59.000Z

87

The 27–28 October 1986 FIRE IFO Cirrus Case Study: Cloud Optical Properties Determined by High Spectral Resolution Lidar  

Science Conference Proceedings (OSTI)

During the FIRE cirrus IFO, the High Spectral Resolution Lidar (HSRL) was operated from a roof top site on the University of Wisconsin–Madison campus. Because the HSRL technique separately measures the molecular and cloud particle backscatter ...

C. J. Grund; E. W. Eloranta

1990-11-01T23:59:59.000Z

88

Detection of Multilayer Cirrus Cloud Systems Using AVHRR Data: Verification Based on FIRE II IFO Composite Measurements  

Science Conference Proceedings (OSTI)

A numerical scheme has been developed to identify multilayer cirrus cloud systems using Advanced Very Higher Resolution Radiometer (AVHRR) data. It is based on the physical properties of the AVHRR channels 1?2 reflectance ratios, the brightness ...

S. C. Ou; K. N. Liou; B. A. Baum

1996-02-01T23:59:59.000Z

89

Demonstration Measurements of Water Vapor, Cirrus Clouds, and Carbon Dioxide Using a High-Performance Raman Lidar  

Science Conference Proceedings (OSTI)

Profile measurements of atmospheric water vapor, cirrus clouds, and carbon dioxide using the Raman Airborne Spectroscopic lidar (RASL) during ground-based, upward-looking tests are presented here. These measurements improve upon any previously ...

David N. Whiteman; Kurt Rush; Igor Veselovskii; Martin Cadirola; Joseph Comer; John R. Potter; Rebecca Tola

2007-08-01T23:59:59.000Z

90

Cirrus Cloud Microphysical Property Retrieval Using Lidar and Radar Measurements. Part I: Algorithm Description and Comparison with In Situ Data  

Science Conference Proceedings (OSTI)

A retrieval algorithm is described to estimate vertical profiles of cirrus-cloud ice water content (IWC) and general effective size Dge from combined lidar and radar measurements. In the algorithm, the lidar extinction coefficient ? is ...

Zhien Wang; Kenneth Sassen

2002-03-01T23:59:59.000Z

91

Tropical Warm Pool International Cloud Experiment (TWP-ICE): Cloud and Rain Characteristics in the Australian Monsoon  

SciTech Connect

The impact of oceanic convection on its environment and the relationship between the characteristics of the convection and the resulting cirrus characteristics is still not understood. An intense airborne measurement campaign combined with an extensive network of ground-based observations is being planned for the region near Darwin, Northern Australia, during January-February, 2006, to address these questions. The Tropical Warm Pool – International Cloud Experiment (TWP-ICE) will be the first field program in the tropics that attempts to describe the evolution of tropical convection, including the large scale heat, moisture, and momentum budgets, while at the same time obtaining detailed observations of cloud properties and the impact of the clouds on the environment. The emphasis will be on cirrus for the cloud properties component of the experiment. Cirrus clouds are ubiquitous in the tropics and have a large impact on their environment but the properties of these clouds are poorly understood. A crucial product from this experiment will be a dataset suitable to provide the forcing and testing required by cloud-resolving models and parameterizations in global climate models. This dataset will provide the necessary link between cloud properties and the models that are attempting to simulate them. The experiment is a collaboration between the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Program, the Bureau of Meteorology (BoM), the National Aeronautics and Space Administration (NASA), the European Commission DG RTD-1.2, and several United States, Australian, Canadian, and European Universities. This experiment will be undertaken over a 4-week period in early 2006. January and February corresponds to the wet phase of the Australia monsoon. This season has been selected because, despite Darwin’s coastal location, the convection that occurs over and near Darwin at this time is largely of maritime origin with a large fetch over water. Based on previous experiments, the convection appears typical of maritime convection with widespread convection that has complex organization, but is not as deep or as intense as continental or coastal convection. Therefore, it is expected that the convection and cloud characteristics will be representative of conditions typical for wide areas of the tropics.

PT May; C Jakob; JH Mather

2004-05-30T23:59:59.000Z

92

Lidar Observation of the Cirrus Cloud in the Tropopause at Chung-Li (25°N, 121°E)  

Science Conference Proceedings (OSTI)

The authors have detected a cirrus cloud near the tropopause by using a lidar system located at Chung-Li, Taiwan (25°N, 121°E). The cloud usually appeared between the month of May and September. In 1993–95, the cloud was observed almost 50% of ...

J. B. Nee; C. N. Len; W. N. Chen; C. I. Lin

1998-06-01T23:59:59.000Z

93

The 27–28 October 1986 FIRE IFO Cirrus Case Study: Spectral Properties of Cirrus Clouds in the 8–12 ?m Window  

Science Conference Proceedings (OSTI)

Lidar and high spectral resolution infrared radiance observations taken on board the ER-2 on 28 October 1986 are used to study the radiative properties of cirrus cloud in the 8–12 ?m window region. Measurements from the High-spectral resolution ...

Steven A. Ackerman; W. L. Smith; H. E. Revercomb; J. D. Spinhirne

1990-11-01T23:59:59.000Z

94

Detecting Cirrus-Overlapping-Water Clouds and Retrieving their...  

NLE Websites -- All DOE Office Websites (Extended Search)

Different methods have been proposed to detect multilayer clouds using passive remote sensing data. Baum et al. (1995) used the CO 2 -slicing technique applied to the...

95

ARM - Field Campaign - WB57 Midlatitude Cirrus Cloud Experiment...  

NLE Websites -- All DOE Office Websites (Extended Search)

invested considerable effort in characterizing clouds with instruments ranging from passive remote sensors on board the EOS platforms, to active remote sensors on Cloudsat and...

96

Homogeneous Nucleation Rate for Highly Supercooled Cirrus Cloud Droplets  

Science Conference Proceedings (OSTI)

A mixed-phase hydrometer growth model has been applied to determining the nucleation mode and rate responsible for the glaciation of a highly supercooled liquid cloud studied jointly by ground-based polarization lidar and aircraft in situ probes. ...

Kenneth Sassen; Gregory C. Dodd

1988-04-01T23:59:59.000Z

97

A Model Predicting the Evolution of Ice Particle Size Spectra and Radiative Properties of Cirrus Clouds. Part I: Microphysics  

Science Conference Proceedings (OSTI)

A Lagrangian time-dependent three-dimensional model was developed that predicts the evolution of ice particle size spectra in cirrus clouds in terms of the growth processes of vapor diffusion and aggregation, as well as the cloud updraft profile. ...

David L. Mitchell

1994-03-01T23:59:59.000Z

98

A Study of Cirrus Ice Particle Size Distribution Using TC4 Observations  

Science Conference Proceedings (OSTI)

An analysis of two days of in situ observations of ice particle size spectra, in convectively generated cirrus, obtained during NASA’s Tropical Composition, Cloud, and Climate Coupling (TC4) mission is presented. The observed spectra are examined ...

Lin Tian; Gerald M. Heymsfield; Lihua Li; Andrew J. Heymsfield; Aaron Bansemer; Cynthia H. Twohy; Ramesh C. Srivastava

2010-01-01T23:59:59.000Z

99

Cirrus Microphysical Properties and Air Motion Statistics Using Cloud Radar Doppler Moments. Part II: Climatology  

Science Conference Proceedings (OSTI)

The algorithm described in Part I has been applied to the millimeter cloud radar observations from January 1999 to December 2005 at the Atmospheric Radiation Measurement Program (ARM) Southern Great Plains (SGP) and Tropical Western Pacific (...

Min Deng; Gerald G. Mace

2008-12-01T23:59:59.000Z

100

Possible Influence of Anthropogenic Aerosols on Cirrus Clouds and Anthropogenic Forcing  

DOE Green Energy (OSTI)

Cirrus clouds have a net warming effect on the atmosphere and cover about 30% of the Earth’s area. Aerosol particles initiate ice formation in the upper troposphere through modes of action that include homogeneous freezing of solution droplets, heterogeneous nucleation on solid particles immersed in a solution, and deposition nucleation of vapor onto solid particles. Here, we examine the possible change in ice number concentration from anthropogenic soot originating from surface sources of fossil fuel and biomass burning, from anthropogenic sulfate aerosols, and from aircraft that deposit their aerosols directly in the upper troposphere. We find that fossil fuel and biomass burning soot aerosols exert a radiative forcing of -0.68 to 0.01 Wm-2 while anthropogenic sulfate aerosols exert a forcing of -0.01 to 0.18 Wm-2. Our calculations show that the sign of the forcing by aircraft soot depends on the model configuration and can be both positive or negative, ranging from -0.16 to 0.02 Wm-2. The magnitude of the forcing in cirrus clouds can be comparable to the forcing exerted by anthropogenic aerosols on warm clouds, but this forcing has not been included in past assessments of the total anthropogenic radiative forcing of climate.

Penner, Joyce E.; Chen, Yang; Wang, Minghuai; Liu, Xiaohong

2009-02-03T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Microphysical and Optical Properties of Cirrus and Contrails: Cloud Field Study on 13 October 1989  

Science Conference Proceedings (OSTI)

During the intensive International Cirrus Experiment conducted over the North Sea during fall 1989, natural cirrus and contrail-induced cirrus were analyzed from in situ and remote sensing measurements (lidar and infrared radiometer). These two ...

Jean-François Gayet; Guy Febvre; Gerard Brogniez; Helene Chepfer; Wolfgang Renger; Peter Wendling

1996-01-01T23:59:59.000Z

102

Satellite-based remote sensing of cirrus clouds: hyperspectral radiative transfer modeling, analysis of uncertainties in in-situ cloud extinction measurements and intercomparison of cirrus retrievals from a-train instruments  

E-Print Network (OSTI)

This dissertation consists of three parts, each devoted to a particular issue of significant importance for satellite-based remote sensing of cirrus clouds. In the first part, we develop and present a fast infrared radiative transfer model on the basis of the adding-doubling principle. The model aims to facilitate the radiative transfer computations involved in hyperspectral remote sensing applications. The model is applicable to a variety of cloud conditions, including vertically inhomogeneous or multilayered clouds. It is shown that for hyperspectral applications the model is two order-of-magnitude faster than the well-known discrete ordinate transfer (DISORT) model, while maintains a similar accuracy. The second part is devoted to the investigation of uncertainties in the FSSP (Forward Scattering Spectrometer Probe) measurement of cloud extinction by small ice particles. First, the single-scattering properties of small ice particles in cirrus clouds are derived and compared to those of equivalent spheres according to various definitions. It is found that, although small ice particles in cirrus clouds are often “quasi-spherical”, their scattering phase functions and asymmetry factors are significant different from those of ice spheres. Such differences may lead to substantial underestimation of cloud extinction in FSSP measurement, if small ice particles are assumed to be spheres. In the third part, we present a comparison of cirrus cloud optical thickness retrievals from two important instruments, MODIS (Moderate Resolution Imaging Spectrometer) and POLDER (Polarization and Directionality of Earth’s Reflection), on board NASA’s A-train satellite constellation. The comparison reveals a large difference. Several possible reasons are discussed. It is found that much of the difference is attributable to the difference between the MODIS and POLDER retrieval algorithm in the assumption of cirrus cloud bulk scattering properties. Potential implications of the difference for climate studies are investigated. An important finding is that the use of an unrealistic cirrus bulk scattering model might introduce artificial seasonal variation of cirrus optical thickness and shortwave radiative forcing into the retrieval.

Zhang, Zhibo

2008-08-01T23:59:59.000Z

103

Microphysical Observations of Tropical Clouds  

Science Conference Proceedings (OSTI)

The results from airborne in situ sampling of convective tropical storms in the Amazon and Kwajalein are presented. Three cases from the Amazon and two from Kwajalein are compared and provide examples of the much larger dataset that was obtained ...

Jeffrey L. Stith; James E. Dye; Aaron Bansemer; Andrew J. Heymsfield; Cedric A. Grainger; Walter A. Petersen; Robert Cifelli

2002-02-01T23:59:59.000Z

104

An Automated Cirrus Cloud Detection Method for a Ground-Based Cloud Image  

Science Conference Proceedings (OSTI)

Cloud detection is a basic research for achieving cloud-cover state and other cloud characteristics. Because of the influence of sunlight, the brightness of sky background on the ground-based cloud image is usually nonuniform, which increases the ...

Jun Yang; Weitao Lu; Ying Ma; Wen Yao

2012-04-01T23:59:59.000Z

105

Retrieval of Tropical Cirrus Thermal Optical Depth, Crystal Size, and Shape Using a Dual-View Instrument at 3.7 and 10.8 ?m  

Science Conference Proceedings (OSTI)

In this paper the authors derive thermal optical depth at 3.7 and 10.8 ?m for tropical cirrus utilizing Along Track Scanning Radiometer data under nighttime conditions. By analytically solving the equation of radiative transfer, inclusive of ...

A. J. Baran; S. J. Brown; J. S. Foot; D. L. Mitchell

1999-01-01T23:59:59.000Z

106

Cirrus Cloud Properties Derived from High Spectral Resolution Infrared Spectrometry during FIRE II. Part III: Ground-Based HIS Results  

Science Conference Proceedings (OSTI)

During FIRE II, cirrus clouds were observed in the wavelength range 3–19, µm with two High Resolution Interferometer Sounders as described in the Part I companion paper. One, known as AC-HIS, was mounted on the NASA ER-2 aircraft in order to look ...

A. D. Collard; S. A. Ackerman; W. L. Smith; X. Ma; H. E. Revercomb; R. O. Knuteson; S-C. Lee

1995-12-01T23:59:59.000Z

107

Experiment to Characterize Tropical Cloud Systems  

SciTech Connect

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.

May, Peter T.; Mather, Jim H.; Jakob, Christian

2005-08-02T23:59:59.000Z

108

Wavelet Analysis of Cirrus Multiscale Structures from Lidar Backscattering: A Cirrus Uncinus Complex Case Study  

Science Conference Proceedings (OSTI)

Although cirrus cloud structures play an important role in dynamics issues, cloud radiative calculations, and cloud parameter retrievals from satellite measurements, fully understanding cirrus cloud structures still remains a challenge. A case ...

Likun Wang; Kenneth Sassen

2008-10-01T23:59:59.000Z

109

Biogeography of Tropical Montane Cloud Forests. Part I: Remote Sensing of Cloud-Base Heights  

Science Conference Proceedings (OSTI)

Cloud-base heights over tropical montane cloud forests are determined using Moderate Resolution Imaging Spectroradiometer (MODIS) cloud products and National Centers for Environmental Prediction global tropospheric final analysis (FNL) fields. ...

Ronald M. Welch; Salvi Asefi; Jian Zeng; Udaysankar S. Nair; Qingyuan Han; Robert O. Lawton; Deepak K. Ray; Vani Starry Manoharan

2008-04-01T23:59:59.000Z

110

Biogeography of Tropical Montane Cloud Forests. Part II: Mapping of Orographic Cloud Immersion  

Science Conference Proceedings (OSTI)

This study details two unique methods to quantify cloud-immersion statistics for tropical montane cloud forests (TMCFs). The first technique uses a new algorithm for determining cloud-base height using Moderate Resolution Imaging ...

Udaysankar S. Nair; Salvi Asefi; Ronald M. Welch; D. K. Ray; Robert O. Lawton; Vani Starry Manoharan; Mark Mulligan; Tom L. Sever; Daniel Irwin; J. Alan Pounds

2008-08-01T23:59:59.000Z

111

Development and Comparison of Ground and Satellite-based Retrievals of Cirrus Cloud Physical Properties  

SciTech Connect

This report is the final update on ARM research conducted at DRI through May of 2006. A relatively minor amount of work was done after May, and last month (November), two journal papers partially funded by this project were published. The other investigator on this project, Dr. Bob d'Entremont, will be submitting his report in February 2007 when his no-cost extension expires. The main developments for this period, which concludes most of the DRI research on this project, are as follows: (1) Further development of a retrieval method for cirrus cloud ice particle effective diameter (De) and ice water path (IWP) using terrestrial radiances measured from satellites; (2) Revision and publication of the journal article 'Testing and Comparing the Modified Anomalous Diffraction Approximation'; and (3) Revision and publication of our radar retrieval method for IWC and snowfall rate.

Mitchell, David L

2009-10-14T23:59:59.000Z

112

Demonstrating the Potential for First-Class Research in Underdeveloped Countries: Research on Stratospheric Aerosols and Cirrus Clouds Optical Properties, and Radiative Effects in Cuba (1988–2010)  

Science Conference Proceedings (OSTI)

Optical properties of stratospheric aerosols and cirrus clouds and their radiative effects are currently important subjects of research worldwide. Those investigations are typical of developed countries, conducted by several highly specialized groups ...

Juan Carlos Antuña Marrero; René Estevan Arredondo; Boris Barja González

2012-07-01T23:59:59.000Z

113

A Lagrangian Interpretation of 3D Tropical Cloud Structure: ...  

NLE Websites -- All DOE Office Websites (Extended Search)

the distributions requires further investigation, the implications are that TWP-Microbase retrieval would provide information about the tropical cloud water content for 2...

114

An Objective Algorithm for Detecting and Tracking Tropical Cloud Clusters: Implications for Tropical Cyclogenesis Prediction  

Science Conference Proceedings (OSTI)

An algorithm to detect and track global tropical cloud clusters (TCCs) is presented. TCCs are organized large areas of convection that form over warm tropical waters. TCCs are important because they are the “seedlings” that can evolve into ...

Christopher C. Hennon; Charles N. Helms; Kenneth R. Knapp; Amanda R. Bowen

2011-08-01T23:59:59.000Z

115

Cirrus Cloud Microphysical Property Retrieval Using Lidar and Radar Measurements. Part II: Midlatitude Cirrus Microphysical and Radiative Properties  

Science Conference Proceedings (OSTI)

The lidar–radar algorithm described in Part I of this set of papers is applied to 1000 h of Raman lidar and millimeter wave cloud radar (MMCR) data collected at the Atmospheric Radiation Measurement program Southern Great Plains Clouds and ...

Zhien Wang; Kenneth Sassen

2002-07-01T23:59:59.000Z

116

The Radiative, Cloud, and Thermodynamic Properties of the Major Tropical Western Pacific Cloud Regimes  

Science Conference Proceedings (OSTI)

This study investigates the radiative, cloud, and thermodynamic characteristics of the atmosphere separated into objectively defined cloud regimes in the tropical western Pacific (TWP). A cluster analysis is applied to 2 yr of daytime-only data ...

Christian Jakob; George Tselioudis; Timothy Hume

2005-04-01T23:59:59.000Z

117

Properties of Tropical Cloud Ensembles Estimated Using a Cloud Model and an Observed Updraft Population  

Science Conference Proceedings (OSTI)

A simple cloud model is developed which is designed for both diagnostic studies and mesoscale cumulus parameterization experiments. The cloud model is combined with an observed population of tropical convective updrafts and used to examine the ...

William M. Frank; Charles Cohen

1985-09-01T23:59:59.000Z

118

Discrimination between thin cirrus and and tropospheric aerosol using  

NLE Websites -- All DOE Office Websites (Extended Search)

Discrimination between thin cirrus and and tropospheric aerosol using Discrimination between thin cirrus and and tropospheric aerosol using multiple measurements from Darwin ARCS Mitchell, Ross CSIRO Category: Aerosols Thin cirrus cloud occurs frequently in the tropics, and is often difficult to distinguish from tropospheric aerosol on the basis of temporal variations in ground based measurements, since both can be rather spatially uniform. In this study we investigate their discrimination by combining data from three instruments at the Darwin Atmospheric Radiation and Cloud Station (ARCS): the Cimel sun photometer (CSP), the micropulse lidar (MPL), and the total sky imager (TSI). The study was carried out over the dry season of 2005, with the usual widespread burning of tropical savanna leading to extensive smoke plumes. It is shown that the locus of data in

119

Microweve Radiative Transfer through Clouds Composed of Realistically Shaped Ice Crystals. Part II. Remote Sensing of Ice Clouds  

Science Conference Proceedings (OSTI)

This paper presents the results of polarized microwave radiative transfer modeling of cirrus clouds containing five different particle shoes and 18 Gamma size distributions. Upwelling brightness temperatures for tropical and midlatitude winter ...

K. Franklin Evans; Graeme L. Stephens

1995-06-01T23:59:59.000Z

120

The Relationship of Highly Reflective Clouds to Tropical Climate Anomalies  

Science Conference Proceedings (OSTI)

The interannual variability of tropical convection related to the Southern Oscillation (SO) and regional climate anomalies is studied from satellite-derived estimates of highly reflective clouds (HRC) during 1971–87. The novel HRC data bank ...

Stefan Hastenrath

1990-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Influence of cloud-radiative forcing on tropical cyclone structure  

Science Conference Proceedings (OSTI)

We demonstrate how and why cloud-radiative forcing (CRF), the interaction of hydrometeors with longwave and shortwave radiation, can influence tropical cyclone structure through “semi-idealized” integrations of the Hurricane Weather Research and ...

Yizhe Peggy Bu; Robert G. Fovell; Kristen L. Corbosiero

122

Limiting Factors for Convective Cloud Top Height in the Tropics  

NLE Websites -- All DOE Office Websites (Extended Search)

Limiting Factors for Convective Cloud Top 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. For climate model applications it is therefore important to understand the factors which determine the type of convective cloud that will occur. In this study, we concentrate on describing the factors that limit the cloud-top heights of mid-

123

Retrieval of Cirrus Cloud Radiative and Backscattering Properties Using Combined Lidar and Infrared Radiometer (LIRAD) Measurements  

Science Conference Proceedings (OSTI)

A method for retrieval of cirrus macrophysical and radiative properties using combined ruby lidar and infrared radiometer measurements is explained in detail. The retrieval algorithm includes estimation of a variable backscatter-to-extinction ...

Jennifer M. Comstock; Kenneth Sassen

2001-10-01T23:59:59.000Z

124

Cirrus Parcel Model Comparison Project. Phase 1: The Critical Components to Simulate Cirrus Initiation Explicitly  

Science Conference Proceedings (OSTI)

The Cirrus Parcel Model Comparison Project, a project of the GCSS [Global Energy and Water Cycle Experiment (GEWEX) Cloud System Studies] Working Group on Cirrus Cloud Systems, involves the systematic comparison of current models of ice crystal ...

Ruei-Fong Lin; David O'C. Starr; Paul J. DeMott; Richard Cotton; Kenneth Sassen; Eric Jensen; Bernd Kärcher; Xiaohong Liu

2002-08-01T23:59:59.000Z

125

Cloud Types and the Tropical Earth Radiation Budget  

Science Conference Proceedings (OSTI)

Nimbus-7 cloud and earth radiation budget data are compared in a study of the effects of clouds on the tropical radiation budget. The data consist of daily averages over fixed (500 km)2 target areas, and the months of July 1979 and January 1980 ...

Harbans L. Dhuria; H. Lee Kyle

1990-12-01T23:59:59.000Z

126

On the Signatures of Equatorial and Extratropical Wave Forcing in Tropical Tropopause Layer Temperatures  

Science Conference Proceedings (OSTI)

Temperatures in the tropical tropopause layer (TTL) play an important role in stratosphere–troposphere exchange and in the formation and maintenance of thin cirrus clouds. Many previous studies have examined the contributions of extratropical and ...

Kevin M. Grise; David W. J. Thompson

2013-04-01T23:59:59.000Z

127

Satellite Observations of Variations in Tropical Cyclone Convection Caused by Upper-Tropospheric Troughs  

Science Conference Proceedings (OSTI)

The mutual adjustment between upper-tropospheric troughs and the structure of western Atlantic Tropical Cyclones Florence (1988) and Irene (1981) are analyzed using satellite and in situ data. Satellite-observed tracers (e.g., cirrus clouds, ...

Edward B. Rodgers; Simon W. Chang; John Stout; Joseph Steranka; Jainn-Jong Shi

1991-08-01T23:59:59.000Z

128

Lagrangian Diagnostics of Tropical Deep Convection and Its Effect upon Upper-Tropospheric Humidity  

Science Conference Proceedings (OSTI)

This study combines geostationary water vapor imagery with optical cloud property retrievals and microwave sea surface observations in order to investigate, in a Lagrangian framework, (i) the importance of cirrus anvil sublimation on tropical ...

Ákos Horváth; Brian J. Soden

2008-03-01T23:59:59.000Z

129

Atmospheric Radiation Measurement Tropical Warm Pool International Cloud Experiment  

NLE Websites -- All DOE Office Websites (Extended Search)

Tropical Warm Pool Tropical Warm Pool International Cloud Experiment General Description The Tropical Warm Pool - International Cloud Experiment (TWP-ICE) was a collaborative effort led by the U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) Program and the Australian Bureau of Meteorology. Beginning January 21 and ending February 14, 2006, the experiment was conducted in the region near the ARM Climate Research Facility in Darwin, Northern Australia. This permanent facility is fully equipped with sophisticated instruments for measuring cloud and other atmospheric properties to provide a long-term record of continuous observational data. Measurements obtained from the other experiment components (explained below) will complement this dataset to provide a detailed description of the tropical atmosphere.

130

Investigation of Thin Cirrus Cloud Optical and Microphysical Properties on the Basis of Satellite Observations and Fast Radiative Transfer Models  

E-Print Network (OSTI)

This dissertation focuses on the global investigation of optically thin cirrus cloud optical thickness (tau) and microphysical properties, such as, effective particle size (D_(eff)) and ice crystal habits (shapes), based on the global satellite observations and fast radiative transfer models (RTMs). In the first part, we develop two computationally efficient RTMs simulating satellite observations under cloudy-sky conditions in the visible/shortwave infrared (VIS/SWIR) and thermal inferred (IR) spectral regions, respectively. To mitigate the computational burden associated with absorption, thermal emission and multiple scattering, we generate pre-computed lookup tables (LUTs) using two rigorous models, i.e., the line-by-line radiative transfer model (LBLRTM) and the discrete ordinates radiative transfer model (DISORT). The second part introduces two methods (i.e., VIS/SWIR- and IR-based methods) to retrieve tau and D_(eff) from satellite observations in corresponding spectral regions of the two RTMs. We discuss the advantages and weakness of the two methods by estimating the impacts from different error sources on the retrievals through sensitivity studies. Finally, we develop a new method to infer the scattering phase functions of optically thin cirrus clouds in a water vapor absorption channel (1.38-µm). We estimate the ice crystal habits and surface structures by comparing the inferred scattering phase functions and numerically simulated phase functions calculated using idealized habits.

Wang, Chenxi

2013-08-01T23:59:59.000Z

131

Comparison of the CALIPSO satellite and ground-based observations of cirrus clouds at the ARM TWP sites  

SciTech Connect

Statistics of ice cloud macrophysical and optical properties from the Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) instrument on board the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite are compared with those from ground-based lidar observations over a 31 month period. Ground-based lidar observations are taken from the micropulse lidars (MPL) at the three Department of Energy Atmospheric Radiation Measurement (ARM) tropical western pacific (TWP) sites: Manus, Nauru and Darwin. CALIPSO observations show a larger cloud fraction at high altitudes while the ground-based MPLs show a larger cloud fraction at low altitudes. The difference in mean ice cloud top and base heights at the Manus and Nauru sites are all within 0.51 km, although differences are statistically significant. Mean ice cloud geometrical thickness agree to within 0.05 km at the Manus and Nauru sites. Larger differences exist at Darwin due to excessive degradation of the MPL output power during our sampling period. Both sets of observations show thicker clouds during the nighttime which may be real but could also be partially an artifact of the decreased signal-to-noise ratio during the daytime. The number of ice cloud layers per profile are also shown to be consistent after accounting for the difference in spatial resolution. For cloud optical depths, four different retrieval methods are compared, two for each set of observations. All products show that the majority of ice cloud optical depths ({approx}60%) fall below an optical depth of 0.2. For most comparisons all four retrievals agree to within the uncertainty intervals. We find that both CALIPSO retrievals agree best to ground-based optical depths when the lidar ratio in the latter is retrieved instead of set to a fixed value. Also thoroughly compared is the cloud properties for the subset of ice clouds which reside in the tropical tropopause layer (TTL).

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

2011-11-10T23:59:59.000Z

132

Spectral Reflectance and Atmospheric Energetics in Cirrus-like Clouds. Part II: Applications of a Fourier-Riccati Approach to Radiative Transfer  

Science Conference Proceedings (OSTI)

One of the major sources of uncertainty in climate studies is the detection of cirrus clouds and characterization of their radiative properties. Combinations of water vapor absorption channels (e.g., 1.38 µm), ice-water absorption channels (e.g., ...

Si-Chee Tsay; Philip M. Gabriel; Michael D. King; Graeme L. Stephens

1996-12-01T23:59:59.000Z

133

Cloud and Radiative Characteristics of Tropical Deep Convective Systems in Extended Cloud Objects from CERES Observations  

Science Conference Proceedings (OSTI)

The physical and radiative properties of tropical deep convective systems for the period from January to August 1998 are examined with the use of Clouds and the Earth’s Radiant Energy System Single-Scanner Footprint (SSF) data from the Tropical ...

Zachary A. Eitzen; Kuan-Man Xu; Takmeng Wong

2009-11-01T23:59:59.000Z

134

Finding Tropical Cyclones on a Cloud Computing Cluster: Using Parallel Virtualization for Large-Scale Climate Simulation Analysis  

E-Print Network (OSTI)

Chang. Changes in Tropical Cyclone Number, Duration, andSimulation of Future Tropical Cyclone Statistics in a High-Finding Tropical Cyclones on a Cloud Computing Cluster:

Hasenkamp, Daren

2011-01-01T23:59:59.000Z

135

Nasa's Tropical Cloud Systems and Processes Experiment  

Science Conference Proceedings (OSTI)

In July 2005, the National Aeronautics and Space Administration investigated tropical cyclogenesis, hurricane structure, and intensity change in the eastern North Pacific and western Atlantic using its ER-2 high-altitude research aircraft. The ...

J. Halverson; M. Black; R. Rogers; S. Braun; G. Heymsfield; D. Cecil; M. Goodman; R. Hood; A. Heymsfield; T. Krishnamurti; G. McFarquhar; M. J. Mahoney; J. Molinari; J. Turk; C. Velden; D-L. Zhang; E. Zipser; R. Kakar

2007-06-01T23:59:59.000Z

136

Small Particles in Cirrus  

NLE Websites -- All DOE Office Websites (Extended Search)

Particles in Cirrus Particles in Cirrus Because the reflective properties of ice crystals in cirrus clouds can greatly influence the amount of solar energy that reaches the Earth, scientists use information about the shape and size of ice crystals as input to climate models. These data are obtained by satellite instruments, ground-based sensors, and research aircraft equipped with probes. However, notable discrepancies among these measurements have led to considerable uncertainty in how to represent these properties in climate models. From December 2009 through April 2010, the Atmospheric Radiation Measurement (ARM) Climate Research Facility will sponsor the use of an instrumented aircraft to obtain the most comprehensive set of measurements of ice crystals in cirrus clouds yet obtained. In conjunction with

137

Microphysics of Venusian Clouds in Rising Tropical Air  

Science Conference Proceedings (OSTI)

As the global distribution of Venusian H2SO4–H2O clouds is strongly related to the global circulation of H2SO4 governed by wind transport and sedimentation of droplets, the circulation of H2SO4 in the Tropics was studied by simultaneously solving ...

Takeshi Imamura; George L. Hashimoto

2001-12-01T23:59:59.000Z

138

Mobile Lidar Profiling of Tropical Aerosols and Clouds  

Science Conference Proceedings (OSTI)

Lidar profiling of atmospheric aerosols and clouds in the lower atmosphere has been in progress at the Indian Institute of Tropical Meteorology (IITM), Pune (18°32?N, 73°52?E, 559 m MSL), India, for more than two decades. To enlarge the scope of ...

P. C. S. Devara; P. E. Raj; K. K. Dani; G. Pandithurai; M. C. R. Kalapureddy; S. M. Sonbawne; Y. J. Rao; S. K. Saha

2008-08-01T23:59:59.000Z

139

Precipitation and Latent Heating Characteristics of the Major Tropical Western Pacific Cloud Regimes  

Science Conference Proceedings (OSTI)

An objective tropical cloud regime classification based on daytime averaged cloud-top pressure and optical thickness information from the International Satellite Cloud Climatology Project (ISCCP) is combined with precipitation and latent heating ...

Christian Jakob; Courtney Schumacher

2008-09-01T23:59:59.000Z

140

A Test of the Simulation of Tropical Convective Cloudiness by a Cloud-Resolving Model  

Science Conference Proceedings (OSTI)

A methodology is described for testing the simulation of tropical convective clouds by models through comparison with observations of clouds and precipitation from earth-orbiting satellites. Clouds are divided into categories that represent ...

Mario A. Lopez; Dennis L. Hartmann; Peter N. Blossey; Robert Wood; Christopher S. Bretherton; Terence L. Kubar

2009-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

A Midlatitude Cirrus Cloud Climatology from the Facility for Atmospheric Remote Sensing. Part III: Radiative Properties  

Science Conference Proceedings (OSTI)

In Part III of a series of papers describing the extended time high-cloud observations from the University of Utah Facility for Atmospheric Remote Sensing (FARS) supporting the First International Satellite Cloud Climatology Project (ISCCP) ...

Kenneth Sassen; Jennifer M. Comstock

2001-08-01T23:59:59.000Z

142

Water Vapor, Condensed Water, and Crystal Concentration in Orographically Influenced Cirrus Clouds  

Science Conference Proceedings (OSTI)

Results are presented from measurements made with a counterflow virtual impactor (CVI) in cirriform clouds containing crystals with dimensions typically less than 30 ?m. Independent measurements of crystal number concentration and cloud water ...

Johan Ström; Jost Heintzenberg

1994-08-01T23:59:59.000Z

143

Gazing at Cirrus Clouds for 25 Years through a Split Window. Part I: Methodology  

Science Conference Proceedings (OSTI)

This paper demonstrates that the split-window approach for estimating cloud properties can improve upon the methods commonly used for generating cloud temperature and emissivity climatologies from satellite imagers. Because the split-window ...

Andrew K. Heidinger; Michael J. Pavolonis

2009-06-01T23:59:59.000Z

144

Application of AVHRR/3 Imagery for the Improved Detection of Thin Cirrus Clouds and Specification of Cloud-Top Phase  

Science Conference Proceedings (OSTI)

A multisensor, data fusion technique has been developed that merges the spectral signatures of ice and water clouds in Advanced Very High Resolution Radiometer (AVHRR) imagery with cloud-top pressure analyses derived from the High-Resolution ...

Keith D. Hutchison

1999-12-01T23:59:59.000Z

145

In Situ Observations of the Microphysical Properties of Wave, Cirrus, and Anvil Clouds. Part I: Wave Clouds  

Science Conference Proceedings (OSTI)

The microphysical properties of wave clouds based on data collected during 17 missions flown by a Learjet research aircraft are presented and discussed. This extensive dataset expands upon previous aircraft studies of wave clouds and introduces ...

Brad A. Baker; R. Paul Lawson

2006-12-01T23:59:59.000Z

146

Radiative Forcing of Simulated Tropical Cloud Clusters  

Science Conference Proceedings (OSTI)

A number of field experiments and subsequent studies in the 1970s and 1980s have led to the belief that radiative processes play a more significant role in the evolution of tropical mesoscale convective systems (MCSS) than was once thought. In ...

Rosemary Auld Miller; William M. Frank

1993-02-01T23:59:59.000Z

147

Microphysical and Radiative Effects of Ice Clouds on Tropical Equilibrium States: A Two-Dimensional Cloud-Resolving Modeling Study  

Science Conference Proceedings (OSTI)

The microphysical and radiative effects of ice clouds on tropical equilibrium states are investigated based on three two-dimensional cloud-resolving simulations imposed by zero vertical velocity and time-invariant zonal wind and sea surface ...

Fan Ping; Zhexian Luo; Xiaofan Li

2007-07-01T23:59:59.000Z

148

Lidar Network Observations of Cirrus Morphological and Scattering Properties during the International Cirrus Experiment 1989: The 18 October 1989 Case Study and Statistical Analysis  

Science Conference Proceedings (OSTI)

Four lidars located roughly 75 km from each other in the inner German Bight of the North Sea, were used to measure geometrical and optical properties of cirrus clouds during the International Cirrus Experiment 1989 (ICE '89). A complete cirrus ...

Albert Ansmann; Jens Bösenberg; Gérard Brogniez; Salem Elouragini; Pierre H. Flamant; Karlheinz Klapheck; Holger Linn; Louis Menenger; Walfried Michaelis; Maren Riebesell; Christoph Senff; Pierre-Yves Thro; Ulla Wandinger; Claus Weitkamp

1993-10-01T23:59:59.000Z

149

Diurnal effects in the composition of cirrus clouds Kenneth Sassen,1  

E-Print Network (OSTI)

measurements discriminate cloud phase and yield indications of ice particle shape and orientation [Sassen 2003; published 30 May 2003. [1] Extended (7-y) polarization lidar data, which are sensitive to ice parameterizations that treat the diurnal frequen- cies of some obvious cloud candidates such as cumulo- nimbus

Liou, K. N.

150

Development and Test of a Cirrus Parameterization Scheme Using NCAR CCM3  

Science Conference Proceedings (OSTI)

Recent research has shown that depending on the cloud properties, cirrus clouds can either increase or decrease the overall heating of the earth–atmosphere system. Hence, the representation of cirrus clouds in GCMs is recognized as an important ...

Dan?e Zurovac-Jevti?; Guang J. Zhang

2003-06-01T23:59:59.000Z

151

The Impact of Ice Phase Cloud Parameterizations on Tropical Cyclone Prediction  

Science Conference Proceedings (OSTI)

The impact of ice phase cloud microphysical processes on prediction of tropical cyclone environment is examined for two microphysical parameterizations using the Coupled Ocean / Atmosphere Mesoscale Prediction System –Tropical Cyclone model. An ...

Yi Jin; Shouping Wang; Jason Nachamkin; James D. Doyle; Gregory Thompson; Louis Grasso; Teddy Holt; Jon Moskaitis; Hao Jin; Richard M. Hodur; Qingyun Zhao; Ming Liu; Mark DeMaria

152

Wavelet Analysis of Simulated Tropical Convective Cloud Systems. Part I: Basic Analysis  

Science Conference Proceedings (OSTI)

A wavelet analysis of a three-dimensional 7-day explicit simulation of the tropical cloud systems in the Global Atmosphere Research Programme (GARP) Atlantic Tropical Experiment Phase III is performed. Three physically distinct regimes (squall ...

Jun-Ichi Yano; Mitchell W. Moncrieff; Xiaoqing Wu; Michio Yamada

2001-04-01T23:59:59.000Z

153

A GCM Parameterization of Ice Particle Mean Effective Sizes for High Latitude Cirrus Clouds and It's Comparison with Mid-Latitude Parmaterization  

NLE Websites -- All DOE Office Websites (Extended Search)

GCM Parameterization of Ice Particle Mean Effective GCM Parameterization of Ice Particle Mean Effective Sizes for High Latitude Cirrus Clouds and It's Comparison with Mid-Latitude Parameterization F. S. Boudala Department of Oceanography Dalhousie University Halifax, Nova Scotia, Canada Q. Fu Department of Atmospheric Sciences University of Washington Seattle, Washington G. A. Issac Meteorological Service of Canada Toronto, Ontario, Canada Introduction Single-scattering properties of ice clouds depend on both ice water content (IWC) and effective size of cloud particles (Fu 1996; Fu et al. 1998). However, only the IWC information is provided in numerical models. Stephens et al. (1990) showed that the ice cloud feedback on a CO 2 warming simulation could be either positive or negative depending on the value of the ice particle size assumed. Parameterizations

154

Relationship between Cloud Radiative Forcing and Sea Surface Temperatures over the Entire Tropical Oceans  

Science Conference Proceedings (OSTI)

Satellite measurements from January 1985 to December 1989 show that warmer tropical oceans as a whole are associated with less longwave greenhouse effect of clouds and less cloud reflection of solar radiation to the space. The regression slopes ...

M. H. Zhang; R. D. Cess; S. C. Xie

1996-06-01T23:59:59.000Z

155

Microphysical Processes Evident in Aerosol Forcing of Tropical Deep Convective Clouds  

Science Conference Proceedings (OSTI)

This study investigates the effects of aerosols on tropical deep convective clouds (DCCs). A series of large-scale, two-dimensional cloud-resolving model simulations was completed, differing only in the concentration of aerosols available to act ...

Rachel L. Storer; Susan C. van den Heever

2013-02-01T23:59:59.000Z

156

Inclusion of Mesoscale Updrafts and Downdrafts in Computations of Vertical Fluxes by Ensembles of Tropical Clouds  

Science Conference Proceedings (OSTI)

Ensembles of convective clouds, especially in the tropics, often have widespread precipitating anvils associated with their deeper convective clouds. Mesoscale downdrafts occur below the middle-level bases of the anvils, and mesoscale updrafts ...

Robert A. Houze Jr.; Chee-Pong Cheng

1981-08-01T23:59:59.000Z

157

On the Observed Near Cancellation between Longwave and Shortwave Cloud Forcing in Tropical Regions  

Science Conference Proceedings (OSTI)

Observations based on Earth Radiation Budget Experiment (ERBE) satellite data indicate that there is a near cancellation between tropical longwave and shortwave cloud forcing in regions of deep convective activity. Cloud forcing depends on both ...

J. T. Kiehl

1994-04-01T23:59:59.000Z

158

Fluctuations of Cloud, Humidity, and Thermal Structure near the Tropical Tropopause  

Science Conference Proceedings (OSTI)

Thermal and humidity structures near the tropical tropopause are studied using microwave satellite retrievals of water vapor, along with contemporaneous dynamical structure in ECMWF analyses and cold clouds in high-resolution global cloud ...

Murry Salby; Fabrizio Sassi; Patrick Callaghan; William Read; Hugh Pumphrey

2003-11-01T23:59:59.000Z

159

Tropical Water Vapor and Cloud Feedbacks in Climate Models: A Further Assessment Using Coupled Simulations  

Science Conference Proceedings (OSTI)

By comparing the response of clouds and water vapor to ENSO forcing in nature with that in Atmospheric Model Intercomparison Project (AMIP) simulations by some leading climate models, an earlier evaluation of tropical cloud and water vapor ...

De-Zheng Sun; Yongqiang Yu; Tao Zhang

2009-03-01T23:59:59.000Z

160

Removal of the Solar Component in AVHRR 3.7-µm Radiances for the Retrieval of Cirrus Cloud Parameters  

Science Conference Proceedings (OSTI)

A numerical scheme has been developed to remove the solar component in the Advanced Very High Resolution Radiometer (AVHRR) 3.7-µm channel for the retrieval of cirrus parameters during daytime. This method uses a number of prescribed threshold ...

N. X. Rao; S. C. Ou; K. N. Liou

1995-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Inference of Cirrus Cloud Properties Using Satellite-observed Visible and Infrared Radiances. Part I: Parameterization of Radiance Fields  

Science Conference Proceedings (OSTI)

Current techniques for deriving cirrus optical depth and altitude from visible (0.65 ?m) and infrared (11.5 ?m) satellite data use radiative transfer calculations based on scattering phase functions of spherical water droplets. This study ...

Patrick Minnis; Kuo-Nan Liou; Yoshihide Takano

1993-05-01T23:59:59.000Z

162

Optical Depth Measurements of Aerosol Cloud, and Water Vapor Using Sun Photometers during FIRE Cirrus IFO II  

Science Conference Proceedings (OSTI)

Optical depths in the visible to infrared spectral region were obtained from solar extinction measurements with two sun photometers during the First ISCCP Regional Experiment Phase II Cirrus Intensive Field Observation in Kansas.

Masataka Shiobara; James D. Spinhirne; Akihiro Uchiyama; Shoji Asano

1996-01-01T23:59:59.000Z

163

Anvil Characteristics as Seen by C-POL during the Tropical Warm Pool International Cloud Experiment (TWP-ICE)  

Science Conference Proceedings (OSTI)

The Tropical Pacific Warm Pool International Cloud Experiment (TWP-ICE) took place in Darwin, Australia, in early 2006. C-band radar data were used to characterize tropical anvil (i.e., thick, nonprecipitating cloud associated with deep ...

Kaycee Frederick; Courtney Schumacher

2008-01-01T23:59:59.000Z

164

Dynamic Effects on the Tropical Cloud Radiative Forcing and Radiation Budget  

Science Conference Proceedings (OSTI)

Vertical velocity is used to isolate the effect of large-scale dynamics on the observed radiation budget and cloud properties in the tropics, using the methodology suggested by Bony et al. Cloud and radiation budget quantities in the tropics show ...

Jian Yuan; Dennis L. Hartmann; Robert Wood

2008-06-01T23:59:59.000Z

165

Molecular Hydrogen in Infrared Cirrus  

E-Print Network (OSTI)

We combine data from our recent FUSE survey of interstellar molecular hydrogen absorption toward 50 high-latitude AGN with COBE-corrected IRAS 100 micron emission maps to study the correlation of infrared cirrus with H2. A plot of the H2 column density vs. IR cirrus intensity shows the same transition in molecular fraction, f_H2, as seen with total hydrogen column density, N_H. This transition is usually attributed to H2 self-shielding, and it suggests that many diffuse cirrus clouds contain H2 in significant fractions, f_H2 = 1-30%. These clouds cover approximately 50% of the northern sky at latitudes b > 30 degrees, at temperature-corrected 100 micron intensities D_100 > 1.5 MJy/sr. The sheetlike cirrus clouds, with hydrogen densities n_H > 30 cm^-3, may be compressed by dynamical processes at the disk-halo interface, and they are conducive to H2 formation on grain surfaces. Exploiting the correlation between N(H2) and 100 micron intensity, we estimate that cirrus clouds at b > 30 contain approximately 3000 M_sun in H2. Extrapolated over the inner Milky Way, the cirrus may contain 10^7 M_sun of H2 and 10^8 M_sun in total gas mass. If elevated to 100 pc, their gravitational potential energy is ~10^53 erg.

Kristen Gillmon; J. Michael Shull

2005-07-25T23:59:59.000Z

166

The Pre-Depression Investigation of Cloud-Systems in the Tropics (PREDICT) Field Campaign: Perspectives of Early Career Scientists  

Science Conference Proceedings (OSTI)

The Pre-Depression Investigation of Cloud-systems in the Tropics (PREDICT) field experiment successfully gathered data from four developing and four decaying/nondeveloping tropical disturbances over the tropical North Atlantic basin between 15 August and ...

Clark Evans; Heather M. Archambault; Jason M. Cordeira; Cody Fritz; Thomas J. Galarneau Jr.; Saska Gjorgjievska; Kyle S. Griffin; Alexandria Johnson; William A. Komaromi; Sarah Monette; Paytsar Muradyan; Brian Murphy; Michael Riemer; John Sears; Daniel Stern; Brian Tang; Segayle Thompson

2012-02-01T23:59:59.000Z

167

The Role of Radiation in Influencing Tropical Cloud Distributions in a Radiative–Convective Equilibrium Cloud-Resolving Model  

Science Conference Proceedings (OSTI)

Observations by Johnson et al. depict regions of active tropical convection as possessing increased relative humidity through a deep layer and reduced low-level static stability when compared to nonconvecting regions. Shallow cumulus clouds, ...

Lyle Pakula; Graeme L. Stephens

2009-01-01T23:59:59.000Z

168

The Size Distribution and Mass-Weighted Terminal Velocity of Low-Latitude Tropopause Cirrus Crystal Populations  

Science Conference Proceedings (OSTI)

Ice crystal terminal velocities govern the lifetime of radiatively complex, climatologically important, low-latitude tropopause cirrus clouds. To better understand cloud lifetimes, the terminal velocities of low-latitude tropopause cirrus cloud ...

C. G. Schmitt; A. J. Heymsfield

2009-07-01T23:59:59.000Z

169

Testing the Role of Radiation in Determining Tropical Cloud-Top Temperature  

Science Conference Proceedings (OSTI)

A cloud-resolving model is used to test the hypothesis that radiative cooling by water vapor emission is the primary control on the temperature of tropical anvil clouds. The temperature of ice clouds in the simulation can be increased or decreased ...

Bryce E. Harrop; Dennis L. Hartmann

2012-09-01T23:59:59.000Z

170

The Implications of Tropical Rossby Waves for Tropical Tropopause Cirrus Formation and for the Equatorial Upwelling of the Brewer–Dobson Circulation  

Science Conference Proceedings (OSTI)

This study puts forward a mechanism for the observed upwelling in the tropical upper troposphere and lower stratosphere. In this hypothesis, the tropical upwelling is driven by momentum transport by Rossby waves that are generated by tropical ...

Matthew T. Boehm; Sukyoung Lee

2003-01-01T23:59:59.000Z

171

Cirrus Classification at Midlatitude from Systematic Lidar Observations  

Science Conference Proceedings (OSTI)

Systematic cirrus lidar measurements performed in the south of France during 2000 are analyzed statistically to search for cloud classes. The classes are based on cloud characteristics (cloud thickness, light backscattering efficiency, and its ...

P. Keckhut; F. Borchi; S. Bekki; A. Hauchecorne; M. SiLaouina

2006-02-01T23:59:59.000Z

172

Selection of the 1.375-µm MODIS Channel for Remote Sensing of Cirrus Clouds and Stratospheric Aerosols from Space  

Science Conference Proceedings (OSTI)

Using spectral imaging data acquired with the Airborne Visible Infrared Imaging Spectrometer (AVIRIS) from an ER-2 aircraft at 20-km altitude during the NASA FIRE Phase II Cirrus field program, it was found that narrow channels near the center of ...

Bo-Cai Gao; Yoram J. Kaufman

1995-12-01T23:59:59.000Z

173

The cloud condensation nuclei and ice nuclei effects on tropical anvil characteristics and water vapor of the tropical tropopause layer  

SciTech Connect

Cloud anvils from deep convective clouds are of great importance to the radiative energy budget and the aerosol impact on them is the least understood. Few studies examined the effects of both cloud condensation nuclei (CCN) and ice nuclei (IN) on anvil properties and water vapor content (WVC) in the Tropical Tropopause Layer (TTL). Using a 3-dimensional cloud-resolving model with size-resolved cloud microphysics, we focus on the CCN and IN effects on cloud anvil properties and WVC in the TTL. We find that cloud microphysical changes induced by CCN/IN play a very important role in determining cloud anvil area and WVC in the TTL, whether convection is enhanced or suppressed. Also, CCN effects on anvil microphysical properties, anvil size and lifetime are much more evident relative to IN. IN has little effect on convection, but can increase ice number and mass concentrations significantly under humid conditions. CCN in the PBL is found to have greater effects on convective strength and mid-tropospheric CCN has negligible effects on convection and cloud properties. Convective transport may only moisten the main convective outflow region but the cloud anvil size determines the WVC in the TTL domain. This study shows an important role of CCN in the lower-troposphere in modifying convection, the upper-level cloud properties. It also shows the effects of IN and the PBL CCN on the upper-level clouds depends on the humidity, resolving some contradictory results in past studies. 2

Fan, Jiwen; Comstock, Jennifer M.; Ovchinnikov, Mikhail

2010-11-10T23:59:59.000Z

174

Cloud Clusters and Tropical Cyclogenesis: Developing and Nondeveloping Systems and Their Large-Scale Environment  

Science Conference Proceedings (OSTI)

Tropical cyclone (TC) genesis occurs only when there is persistent, organized convection. The question of why some cloud clusters develop into a TC and others do not remains unresolved. This question cannot be addressed adequately without studying ...

Brandon W. Kerns; Shuyi S. Chen

2013-01-01T23:59:59.000Z

175

A 10-Year Climatology of Northern Hemisphere Tropical Cloud Plumes and Their Composite Flow Patterns  

Science Conference Proceedings (OSTI)

A 10-year cool season climatology of tropical cloud plumes in the Northern Hemisphere was generated by visual inspection of infrared satellite imagery. The sample included 1062 plume events during the months of October to May for the years 1974 ...

Haig Iskenderian

1995-06-01T23:59:59.000Z

176

Microwave Simulations of a Tropical Rainfall System with a Three-Dimensional Cloud Model  

Science Conference Proceedings (OSTI)

A three-dimensional cloud model-microwave radiative transfer model combination is used to study the relations among the precipitation and other microphysical characteristics of a tropical oceanic squall line and the upwelling radiance at ...

Robert F. Adler; Hwa-Young M. Yeh; N. Prasad; Wei-Kuo Tao; Joanne Simpson

1991-07-01T23:59:59.000Z

177

Observations of Record Cold Cloud-Top Temperatures in Tropical Cyclone Hilda (1990)  

Science Conference Proceedings (OSTI)

A detailed analysis is made of the development of a region of cold cloud-top temperatures in Tropical Cyclone Hilda (1990) in the Coral Sea off eastern Australia. Observed temperatures of approximately 173 K (?100°C) from two independent ...

Elizabeth E. Ebert; Greg J. Holland

1992-10-01T23:59:59.000Z

178

Environment and the Lifetime of Tropical Deep Convection in a Cloud-Permitting Regional Model Simulation  

Science Conference Proceedings (OSTI)

By applying a cloud tracking algorithm to tropical convective systems in a simulated a regional high resolution model simulation, this study documents the environmental conditions before and after convective systems are initiated over ocean and ...

Samson Hagos; Zhe Feng; Sally McFarlane; L. Ruby Leung

179

A Climatology of Surface Cloud Radiative Effects at the ARM Tropical Western Pacific Sites  

Science Conference Proceedings (OSTI)

Cloud radiative effects on surface downwelling fluxes are investigated using datasets from the Atmospheric Radiation Measurement Program (ARM) sites in the tropical western Pacific Ocean (TWP) region. The Nauru Island (Republic of Nauru) and ...

Sally A. McFarlane; Charles N. Long; Julia Flaherty

2013-04-01T23:59:59.000Z

180

Response of Tropical Clouds to the Interannual Variation of Sea Surface Temperature  

Science Conference Proceedings (OSTI)

Connections between the large-scale interannual variations of clouds, deep convection, atmospheric winds, vertical thermodynamic structure, and SSTs over global tropical oceans are examined over the period July 1983-December 1990. The SST warming ...

Rong Fu; W. Timothy Liu; Robert E. Dickinson

1996-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Clouds, Radiation, and the Diurnal Cycle of Sea Surface Temperature in the Tropical Western Pacific  

Science Conference Proceedings (OSTI)

The relationship among clouds, surface radiation flux, and the sea surface temperature (SST) of the tropical western Pacific Ocean over the diurnal cycle is addressed in the context of the Atmospheric Radiation Measurement (ARM) Program ...

Peter J. Webster; Carol Anne Clayson; Judith A. Curry

1996-08-01T23:59:59.000Z

182

Environment and the Lifetime of Tropical Deep Convection in a Cloud-Permitting Regional Model Simulation  

Science Conference Proceedings (OSTI)

By applying a cloud-tracking algorithm to tropical convective systems in a regional high-resolution model simulation, this study documents the environmental conditions before and after convective systems are initiated over ocean and land by ...

Samson Hagos; Zhe Feng; Sally McFarlane; L. Ruby Leung

2013-08-01T23:59:59.000Z

183

On the Identification of the Large-Scale Properties of Tropical Convection using Cloud Regimes  

Science Conference Proceedings (OSTI)

The use of cloud regimes in identifying tropical convection and the associated large-scale atmospheric properties is investigated. The regimes are derived by applying cluster analysis to satellite retrievals of daytime-averaged frequency ...

Jackson Tan; Christian Jakob; Todd P. Lane

184

Reproducibility by Climate Models of Cloud Radiative Forcing Associated with Tropical Convection  

Science Conference Proceedings (OSTI)

In this study, cloud radiative forcing (CRF) associated with convective activity over tropical oceans is analyzed for monthly mean data from twentieth-century simulations of 18 climate models participating in phase 3 of the Coupled Model ...

Hiroki Ichikawa; Hirohiko Masunaga; Yoko Tsushima; Hiroshi Kanzawa

2012-02-01T23:59:59.000Z

185

The Role of Cloud Microphysics Parameterization in the Simulation of Mesoscale Convective System Clouds and Precipitation in the Tropical Western Pacific  

Science Conference Proceedings (OSTI)

This paper presents a detailed analysis of convection-permitting cloud simulations, aimed at increasing the understanding of the role of parameterized cloud microphysics in the simulation of mesoscale convective systems (MCSs) in the tropical ...

K. Van Weverberg; A. M. Vogelmann; W. Lin; E. P. Luke; A. Cialella; P. Minnis; M. Khaiyer; E. R. Boer; M. P. Jensen

2013-04-01T23:59:59.000Z

186

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

SciTech Connect

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.

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

2008-11-20T23:59:59.000Z

187

A Midlatitude Cirrus Cloud Climatology from the Facility for Atmospheric Remote Sensing. Part I: Macrophysical and Synoptic Properties  

Science Conference Proceedings (OSTI)

A uniquely extensive high cloud dataset has been collected from the University of Utah Facility for Atmospheric Remote Sensing in support of the First (ISCCP) International Satellite Cloud Climatology Project Regional Experiment extended time ...

Kenneth Sassen; James R. Campbell

2001-03-01T23:59:59.000Z

188

Intraseasonal Behavior of Clouds, Temperature, and Motion in the Tropics  

Science Conference Proceedings (OSTI)

The spectral character of tropical convection is investigated in an 11-yr record of outgoing longwave radiation from the Advanced Very High Resolution Radiometer to identify interaction with the tropical circulation. Along the equator in the ...

Murry L. Salby; Harry H. Hendon

1994-08-01T23:59:59.000Z

189

Estimation of Cirrus Optical Thickness from Sun Photometer Measurements  

Science Conference Proceedings (OSTI)

A method is proposed to estimate the optical thickness of cirrus clouds from ground-based sun photometry. Transfer calculations of solar radiation in ice clouds were made by the Monte Carlo method. A scattering phase function presented by Takano ...

Masataka Shiobara; Shoji Asano

1994-06-01T23:59:59.000Z

190

TROPIC: transactional resource orchestration platform in the cloud  

Science Conference Proceedings (OSTI)

Realizing Infrastructure-as-a-Service (IaaS) cloud requires a control platform to orchestrate cloud resource provisioning, configuration, and decommissioning across a distributed set of diverse physical resources. This orchestration is challenging due ...

Changbin Liu; Yun Mao; Xu Chen; Mary F. Fernández; Boon Thau Loo; Jacobus E. Van Der Merwe

2012-06-01T23:59:59.000Z

191

Comparison of Cirrus Height and Optical Depth Derived from Satellite and Aircraft Measurements  

Science Conference Proceedings (OSTI)

During the International Cirrus Experiment (ICE'89) simultaneous measurements of Cirrus cloud-top height and optical depth by satellite and aircraft have been taken. Data from the Advanced Very High Resolution Radiometer (AVHRR) onboard the NOAA ...

M. Kästner; K. T. Kriebel; R. Meerkötter; W. Renger; G. H. Ruppersberg; P. Wendling

1993-10-01T23:59:59.000Z

192

Seasonal and Diurnal Changes in Cirrus Clouds as Seen in Four Years of Observations with the VAS  

Science Conference Proceedings (OSTI)

GOES VAS multispectral observations in the carbon dioxide absorption band at 15 ?m have been used to compile cloud-cover statistics over the continental United States for the past 4 years. The CO2 technique calculates both cloud-top pressures and ...

W. P. Menzel; D. P. Wylie; K. I. Strabala

1992-04-01T23:59:59.000Z

193

Cirrus Cloud Properties Derived from POLDER-1/ADEOS Polarized Radiances: First Validation Using a Ground-Based Lidar Network  

Science Conference Proceedings (OSTI)

Bidirectional polarized reflectances measured with the POLDER-1 instrument on board Advanced Earth Observing Satellite-1 have been used to infer cloud altitude and thermodynamical phase (ice/liquid) at a global scale. This paper presents a ...

Hélène Chepfer; Philippe Goloub; James Spinhirne; Pierre H. Flamant; Mario Lavorato; Laurent Sauvage; Gérard Brogniez; Jacques Pelon

2000-02-01T23:59:59.000Z

194

ARM - Publications: Science Team Meeting Documents: Tropical Warm Pool  

NLE Websites -- All DOE Office Websites (Extended Search)

Tropical Warm Pool International Cloud Experiment Tropical Warm Pool International Cloud Experiment May, Peter Bureau or Meteorology Research Centre Mather, James Pacific Northwest National Laboratory Jakob, Christian BMRC One of the most complete data sets describing tropical convection ever collected will result from the upcoming Tropical Warm Pool International Cloud Experiment (TWPICE) in the area around Darwin in late 2005 and early 2006. The aims of the experiment 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 design includes an unprecedented network of ground-based observations (soundings, active and passive remote sensors) combined with a large range of low, mid and high altitude aircraft for in-situ and remote sensing

195

Tropical Intraseasonal Oscillation, Super Cloud Clusters, and Cumulus Convection Schemes  

Science Conference Proceedings (OSTI)

A new framework for interpreting the origin of the tropical intraseasonal oscillation (TISO), which avoids the speed and scale selection problems in the previous theories, is proposed in this study. In this interpretation TISO is viewed as an ...

Winston C. Chao; Shian-Jiann Lin

1994-05-01T23:59:59.000Z

196

Climatology and Formation of Tropical Midlevel Clouds at the Darwin ARM Site  

SciTech Connect

A 4-yr climatology of midlevel clouds is presented from vertically pointing cloud lidar and radar measurements at the Atmospheric Radiation Measurement Program (ARM) site at Darwin, Australia. Few studies exist of tropical midlevel clouds using a dataset of this length. Seventy percent of clouds with top heights between 4 and 8 km are less than 2 km thick. These thin layer clouds have a peak in cloud-top temperature around the melting level (0°C) and also a second peak around -12.5°C. The diurnal frequency of thin clouds is highest during the night and reaches a minimum around noon, consistent with variation caused by solar heating. Using a 1.5-yr subset of the observations, the authors found that thin clouds have a high probability of containing supercooled liquid water at low temperatures: ~20% of clouds at -30°C, ~50% of clouds at -20°C, and ~65% of clouds at -10°C contain supercooled liquid water. The authors hypothesize that thin midlevel clouds formed at the melting level are formed differently during active and break monsoon periods and test this over three monsoon seasons. A greater frequency of thin midlevel clouds are likely formed by increased condensation following the latent cooling of melting during active monsoon periods when stratiform precipitation is most frequent. This is supported by the high percentage (65%) of midlevel clouds with preceding stratiform precipitation and the high frequency of stable layers slightly warmer than 0°C. In the break monsoon, a distinct peak in the frequency of stable layers at 0°C matches the peak in thin midlevel cloudiness, consistent with detrainment from convection.

Riihimaki, Laura D.; McFarlane, Sally A.; Comstock, Jennifer M.

2012-10-01T23:59:59.000Z

197

The Impact of Aircraft Dropsonde and Satellite Wind Data on Numerical Simulations of Two Landfalling Tropical Storms during the Tropical Cloud Systems and Processes Experiment  

Science Conference Proceedings (OSTI)

Dropwindsonde, Geostationary Operational Environmental Satellite-11 (GOES-11) rapid-scan atmospheric motion vectors, and NASA Quick Scatterometer (QuikSCAT) near-surface wind data collected during NASA’s Tropical Cloud Systems and Processes (TCSP)...

Zhaoxia Pu; Xuanli Li; Christopher S. Velden; Sim D. Aberson; W. Timothy Liu

2008-02-01T23:59:59.000Z

198

Building a Tropical–Extratropical Cloud Band Metbot  

Science Conference Proceedings (OSTI)

An automated cloud band identification procedure is developed that captures the meteorology of such events over southern Africa. This “metbot” is built upon a connected component labeling method that enables blob detection in various atmospheric ...

Neil C. G. Hart; Chris J. C. Reason; Nicolas Fauchereau

2012-12-01T23:59:59.000Z

199

Response of Humidity and Clouds to Tropical Deep Convection  

Science Conference Proceedings (OSTI)

Currently available satellite data can be used to track the response of clouds and humidity to intense precipitation events. A compositing technique centered in space and time on locations experiencing high rain rates is used to detail the ...

Mark D. Zelinka; Dennis L. Hartmann

2009-05-01T23:59:59.000Z

200

Radiative and Convective Driving of Tropical High Clouds  

Science Conference Proceedings (OSTI)

Using satellite cloud data from the Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) and collocated precipitation rates from the Advanced Microwave Scanning Radiometer (AMSR), it is shown that rain rate is closely related to the amount ...

Terence L. Kubar; Dennis L. Hartmann; Robert Wood

2007-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

A Climatology of Surface Cloud Radiative Effects at the ARM Tropical Western Pacific Sites  

SciTech Connect

Cloud radiative effects on surface downwelling fluxes are investigated using long-term datasets from the three Atmospheric Radiation Measurement (ARM) sites in the Tropical Western Pacific (TWP) region. The Nauru and Darwin sites show significant variability in sky cover, downwelling radiative fluxes, and surface cloud radiative effect (CRE) due to El Niño and the Australian monsoon, respectively, while the Manus site shows little intra-seasonal or interannual variability. Cloud radar measurement of cloud base and top heights are used to define cloud types so that the effect of cloud type on the surface CRE can be examined. Clouds with low bases contribute 71-75% of the surface shortwave (SW) CRE and 66-74% of the surface longwave (LW) CRE at the three TWP sites, while clouds with mid-level bases contribute 8-9% of the SW CRE and 12-14% of the LW CRE, and clouds with high bases contribute 16-19% of the SW CRE and 15-21% of the LW CRE.

McFarlane, Sally A.; Long, Charles N.; Flaherty, Julia E.

2013-04-01T23:59:59.000Z

202

Study of ice cloud properties using infrared spectral data  

E-Print Network (OSTI)

The research presented in this thesis involves the study of ice cloud microphysical and optical properties using both hyperspectral and narrowband infrared spectral data. First, ice cloud models are developed for the Infrared Atmospheric Sounding Interferometer (IASI) instrument onboard the METOP-A satellite, which provide the bulk-scattering properties of these clouds for the 8461 IASI channels between 645 and 2760 cm-1. We investigate the sensitivity of simulated brightness temperatures in this spectral region to the bulk-scattering properties of ice clouds containing individual ice crystal habits as well as for one habit distribution. The second part of this thesis describes an algorithm developed to analyze the sensitivity of simulated brightness temperatures at 8.5 and 11.0 µm to changes in effective cloud temperature by adjusting cloud top height and geometric thickness in a standard tropical atmosphere. Applicability of using these channels in a bi-spectral approach to retrieve cirrus cloud effective particle size and optical thickness is assessed. Finally, the algorithm is applied to the retrieval of these ice cloud properties for a case of single-layered cirrus cloud over a tropical ocean surface using measurements from the Moderate Resolution Infrared Spectroradiometer (MODIS). Cloud top height and geometric thickness in the profile are adjusted to assess the influence of effective cloud temperature on the retrieval.

Garrett, Kevin James

2007-08-01T23:59:59.000Z

203

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

Science Conference Proceedings (OSTI)

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.

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

2012-09-06T23:59:59.000Z

204

The Development of Midlatitude Cirrus Models for MODIS Using FIRE-I, FIRE-II, and ARM In Situ Data  

Science Conference Proceedings (OSTI)

Detailed in situ data from cirrus clouds have been collected during dedicated field campaigns, but the use of the size and habit distribution data has been lagging in the development of more realistic cirrus scattering models. In this study, the ...

Shaima L. Nasiri; Bryan A. Baum; Andrew J. Heymsfield; Ping Yang; Michael R. Poellot; David P. Kratz; Yongxiang Hu

2002-03-01T23:59:59.000Z

205

Evaluation of Cirrus Parameterizations for Radiative Flux Computations in Climate Models Using TOVS–ScaRaB Satellite Observations  

Science Conference Proceedings (OSTI)

Combined simultaneous satellite observations are used to evaluate the performance of parameterizations of the microphysical and optical properties of cirrus clouds used for radiative flux computations in climate models. Atmospheric and cirrus ...

C. J. Stubenrauch; F. Eddounia; J. M. Edwards; A. Macke

2007-09-01T23:59:59.000Z

206

Effects of Diurnal Variations on Tropical Equilibrium States: A Two-Dimensional Cloud-Resolving Modeling Study  

Science Conference Proceedings (OSTI)

Effects of diurnal variations on tropical heat and water vapor equilibrium states are investigated based on hourly data from two-dimensional cloud-resolving simulations. The model is integrated for 40 days and the simulations reach equilibrium ...

Shouting Gao; Yushu Zhou; Xiaofan Li

2007-02-01T23:59:59.000Z

207

Retrieval of Cloud Water and Water Vapor Contents from Doppler Radar Data in a Tropical Squall Line  

Science Conference Proceedings (OSTI)

This paper describes the retrieval of cloud water and water vapor contents from Doppler radar data. The convective part of a tropical squall line (22 June 1981) observed during the COPT 81 (Convection Profonde Tropicale 1981) West African ...

Danièle Hauser; Paul Amayenc

1986-04-01T23:59:59.000Z

208

Statistical Analysis of the Life Cycle of Isolated Tropical Cold Cloud Systems Using MTSAT-1R and TRMM Data  

Science Conference Proceedings (OSTI)

Observations from the Multifunctional Transport Satellite-1R (MTSAT-1R) and the Tropical Rainfall Measuring Mission (TRMM) satellites are analyzed to show the universal view of the cloud life cycle, including the changes of vertical structure of ...

Keiji Imaoka; Kenji Nakamura

2012-11-01T23:59:59.000Z

209

Convective Influence on the Heat Balance of the Tropical Tropopause Layer: A Cloud-Resolving Model Study  

Science Conference Proceedings (OSTI)

The tropical tropopause layer (TTL), and in particular the cold point tropopause, has been previously suggested as a feature decoupled from convection. Using a cloud-resolving model, the authors demonstrate that convection, in fact, has a cooling ...

Zhiming Kuang; Christopher S. Bretherton

2004-12-01T23:59:59.000Z

210

Multiscale Convective Wave Disturbances in the Tropics: Insights from a Two-Dimensional Cloud-Resolving Model  

Science Conference Proceedings (OSTI)

Multiscale convective wave disturbances with structures broadly resembling observed tropical waves are found to emerge spontaneously in a nonrotating, two-dimensional cloud model forced by uniform cooling. To articulate the dynamics of these ...

Stefan N. Tulich; Brian E. Mapes

2008-01-01T23:59:59.000Z

211

Comparison of the Highly Reflective Cloud and Outgoing Longwave Radiation Datasets for Use in Estimating Tropical Deep Convection  

Science Conference Proceedings (OSTI)

Currently, there are two long-term satellite-derived datasets most are frequently used as indices for tropical deep convection. These are the Outgoing Longwave Radiation (OLR) and Highly Reflective Cloud (HRC) datasets. Although both of these ...

Duane E. Waliser; Nicholas E. Graham; Catherine Gautier

1993-02-01T23:59:59.000Z

212

SPARTICUS: Small Particles in Cirrus Science and Operations Plan  

SciTech Connect

From a mass-weighted perspective, cirrus clouds exert an enormous influence on the radiative energy budget of the earth’s climate system. Owing to their location in the cold upper troposphere, cirrus can significantly reduce the outgoing longwave radiation while, at the same time, remaining relatively transmissive to solar energy. Thus, cirrus clouds are the only cloud genre that can exert a direct radiative warming influence on the climate system (Ackerman et al. 1988). It is not surprising, therefore, that general circulation models (GCMs) are especially sensitive to the presence of cirrus in the model atmosphere. Lohmann and Roeckner (1995), for instance, show that the climate sensitivity can vary by as much as 40% due to the properties of cirrus varying between transparent and opaque limits. Lohmann and Roeckner (1995) also identify a key feedback by cirrus that is often overlooked; on longer time scales cloud heating in the upper troposphere can act to maintain and modulate the general circulation of the atmosphere through accelerating the subtropical and polar jet streams. Understanding these mechanisms and representing them in models is complicated by the fact that cirrus properties vary over an enormous dynamic range compared to most other clouds.

J Mace, E Jensen, G McFarquhar, J Comstock, T Ackerman, D Mitchell, X Liu, T Garrett

2009-10-31T23:59:59.000Z

213

arm_stm_2008_borg_cirrus_poster.ppt  

NLE Websites -- All DOE Office Websites (Extended Search)

Cirrus Cloud Characterization Cirrus Cloud Characterization with Raman Lidar Measurements at Southern Great Plains Lori Borg, David Turner, Robert Holz, David Tobin, Bob Knuteson, Leslie Moy, Daniel DeSlover, Ed Eloranta, Hank Revercomb (PI) Altitude [km] Radar + Lidar Heating Rate [deg/day] Altitude [km] Radar Heating Rate [deg/day] Altitude [km] MMCR Radar Reflectivity [dBZ] (color) with Lidar Boundaries (black) SGP Cirrus Case Study: 11/08/2005 18:00UTC - 11/11/2005 12:00 UTC Lori Borg, lori.borg@ssec.wisc.edu Introduction: Cirrus clouds play a significant role in the energy budget of the atmosphere and represent a major source of uncertainly in understanding climate and climate change. A large part of this uncertainty lies in the modeling of the cloud, which requires assumptions and

214

University of Wisconsin Cirrus Remote Sensing Pilot Experiment  

Science Conference Proceedings (OSTI)

During the period of 26 October 1989 through 6 December 1989 a unique complement of measurements was made at the University of Wisconsin—Madison to study the radiative properties of cirrus clouds. Simultaneous observations were obtained from a ...

Steven A. Ackerman; William L. Smith; Ed W. Eloranta; Chris J. Grund; Robert O. Knuteson; Henry E. Revercomb; Donald P. Wylie

1993-06-01T23:59:59.000Z

215

Effects of diurnal variation on a tropical coupling system: a 2-dimensional coupled ocean-cloud resolving atmosphere modeling study  

Science Conference Proceedings (OSTI)

The effects of diurnal variation on tropical atmospheric and oceanic variability are investigated with a two-dimensional coupled ocean-cloud resolving atmosphere model. The experiment with a time-invariant solar zenith angle is compared to the control ... Keywords: diurnal variation, tropical coupling system

Shouting Gao; Yushu Zhou

2008-05-01T23:59:59.000Z

216

Statistical Dependence of Albedo and Cloud Cover on Sea Surface Temperature for Two Tropical Marine Stratocumulus Regions  

Science Conference Proceedings (OSTI)

The relationship between sea surface temperature (SST) and albedo or cloud cover is examined for two tropical regions with high values of cloud radiative forcing and persistent marine stratocumulus (mSc)–one off the west coast of Peru, the other ...

Lazaros Oreopoulos; Roger Davies

1993-12-01T23:59:59.000Z

217

Simulation of microphysical structure associated with tropical cloud clusters using mesoscale model and comparison with TRMM observations  

Science Conference Proceedings (OSTI)

An attempt has been made in the present study to examine the microphysical structure of a non-squall Tropical Cloud Cluster (TCC). Three-dimensional model simulations of cloud microphysical structure associated with a non-squall TCC occurred on 26 October ...

S. Abhilash; K. Mohankumar; S. Das

2008-04-01T23:59:59.000Z

218

Lidar Investigation of Tropical Nocturnal Boundary Layer Aerosols and Cloud Macrophysics  

SciTech Connect

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.

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

2013-10-01T23:59:59.000Z

219

Obtaining Best Estimates for the Microphysical and Radiative Properties of Tropical Ice Clouds from TWP-ICE In Situ Microphysical Observations  

Science Conference Proceedings (OSTI)

Best estimates of the bulk microphysical and radiative properties (ice water content, visible extinction, effective radius, and total concentration) are derived for three case studies of tropical ice clouds sampled during the Tropical Warm Pool ...

A. Protat; G. M. McFarquhar; J. Um; J. Delanoë

2011-04-01T23:59:59.000Z

220

The Pre-Depression Investigation of Cloud-Systems in the Tropics (PREDICT) Experiment: Scientific Basis, New Analysis Tools, and Some First Results  

Science Conference Proceedings (OSTI)

The principal hypotheses of a new model of tropical cyclogenesis, known as the marsupial paradigm, were tested in the context of Atlantic tropical disturbances during the National Science Foundation (NSF)-sponsored Pre-Depression Investigation of Cloud ...

Michael T. Montgomery; Christopher Davis; Timothy Dunkerton; Zhuo Wang; Christopher Velden; Ryan Torn; Sharanya J. Majumdar; Fuqing Zhang; Roger K. Smith; Lance Bosart; Michael M. Bell; Jennifer S. Haase; Andrew Heymsfield; Jorgen Jensen; Teresa Campos; Mark A. Boothe

2012-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Subvisual-Thin Cirrus Lidar Dataset for Satellite Verification and Climatological Research  

Science Conference Proceedings (OSTI)

A polarization (0.694-?m wavelength) lidar dataset for subvisual and thin (bluish-colored) cirrus clouds is drawn from Project FIRE (First ISCCP Regional Experiment) extended time observations. The clouds are characterized by their day–night ...

Kenneth Sassen; Byung Sung Cho

1992-11-01T23:59:59.000Z

222

Initialization and Validation of a Simulation of Cirrus Using FIRE-II Data  

Science Conference Proceedings (OSTI)

Observations from a wide variety of instruments and platforms are used to validate many different aspects of a three-dimensional mesoscale simulation of the dynamics, cloud microphysics, and radiative transfer of a cirrus cloud system observed on ...

D.L. Westphal; S. Kinne; P. Pilewskie; J.M. Alvarez; P. Minnis; D.F. Young; S.G. Benjamin; W.L. Eberhard; R.A. Kropfli; S.Y. Matrosov; J.B. Snider; T.A. Uttal; A.J. Heymsfield; G.G. Mace; S.H. Melfi; D.O'C. Starr; J.J. Soden

1996-12-01T23:59:59.000Z

223

Cloud to ground lightning in tropical cyclone: a study of 34 West Atlantic tropical cyclones from 1986-1996  

E-Print Network (OSTI)

Cloud to ground (CG) lightning characteristics and patterns were investigated for 34 tropical cyclones for the time period 1986 to 1996. Spatial analysis of CG lightning relative to both compass directions and the direction of motion were compiled. Additionally, a radial analysis of this data was performed within both a 300 km radius and a 50 km radius range. Finally, all analyses were stratified into all tropical cyclones and hurricane categories for further consideration. The National Lightning Detection Network recorded 307,593 CG lightning flashes within 300 km of the storms in this study. Negative flashes had an average first stroke peak current of -49 kA and a mean multiplicity of 2.7. Positive flashes occurred at a rate of 5.3 percent, with a mean peak current of 43 kA and 1.2 multiplicity average. Detected CG lightning characteristics changed significantly with a network upgrade in 1994. CG lightning flashes for all tropical cyclones favored the area south and west of the cyclone center. However, taking into account storm relative motion, the majority of flashes shifts to the front and right sections of the storm. Radial plots indicated lightning frequency increased throughout the domain, with a maximum between 270 km and 300 km. Hurricanes, however, indicated flashes occurred most often in the north and east quadrants. When adjusting for storm motion, the activity shifts to the right with some evidence of individual rainbands in the rear section. Radial plots indicated the increased organization of hurricanes, with a weak maxima in the convective eyewall, a minimum in the stratiform area, and a strong maximum in the outer rainbands. Further analysis indicated a higher frequency of CG lightning flashes in hurricanes suggests a state of hurricane strengthening or weakening. However, there was no direct correlation in the observed lightning frequency with a given change in the central pressure of the hurricane.

Coyne, John Michael

2001-01-01T23:59:59.000Z

224

The Magellan Final Report on Cloud Computing  

E-Print Network (OSTI)

resources. 1. Finding Tropical Cyclones on a Cloud Computing2010 2. Finding Tropical Cyclones on Clouds, D. Hasenkamp

Coghlan, Susan

2013-01-01T23:59:59.000Z

225

An Intercomparison of Microphysical Retrieval Algorithms for Upper-Tropospheric Ice Clouds  

Science Conference Proceedings (OSTI)

The large horizontal extent, with its location in the cold upper troposphere, and ice composition make cirrus clouds important modulators of the Earth's radiation budget and climate. Cirrus cloud microphysical properties are difficult to measure ...

Jennifer M. Comstock; Sally A. McFarlane; Robert d'Entremont; Daniel DeSlover; David D. Turner; Gerald G. Mace; Sergey Y. Matrosov; Matthew D. Shupe; Patrick Minnis; David Mitchell; Kenneth Sassen; Zhien Wang

2007-02-01T23:59:59.000Z

226

Boundary Layer and Cloud Structure Controls on Tropical Low Cloud Cover Using A-Train Satellite Data and ECMWF Analyses  

Science Conference Proceedings (OSTI)

The Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO), CloudSat radar, and the Moderate Resolution Imaging Spectroradiometer (MODIS) cloud data on the A-Train constellation complemented with the European Centre for ...

Terence L. Kubar; Duane E. Waliser; J-L. Li

2011-01-01T23:59:59.000Z

227

The 27–28 October 1986 FIRF IFO Cirrus Case Study: Comparison of Radiative Transfer Theory with Observations by Satellite and Aircraft  

Science Conference Proceedings (OSTI)

Observations of cirrus and altocumulus clouds during the First International Satellite Cloud Climatology Project Regional Experiment (FIRE) are compared to theoretical models of cloud radiative properties. Three tests are performed. First, ...

Bruce A. Wielicki; J.T. Suttles; Andrew J. Heymsfield; Ronald M. Welch; James D. Spinhirne; Man-Li C. Wu; David O'C. Starr; Lindsay Parker; Robert F. Arduini

1990-11-01T23:59:59.000Z

228

Cirrus Outflow Dynamics  

Science Conference Proceedings (OSTI)

Cirrus outflow from deep convection are analyzed as dynamically and thermodynamically active systems. The initial outflow is considered as an analog to wake collapse, in which a neutrally buoyant flow intrusion is flattened and stretched by its ...

Douglas K. Lilly

1988-05-01T23:59:59.000Z

229

Cirrus Crystal Terminal Velocities  

Science Conference Proceedings (OSTI)

Cirrus crystal terminal velocities are of primary importance in determining the rate of transport of condensate from upper- to middle-tropospheric levels and profoundly influence the earth’s radiation balance through their effect on the rate of ...

Andrew J. Heymsfield; Jean Iaquinta

2000-04-01T23:59:59.000Z

230

FINAL REPORT FOR THE DOE/ARM PROJECT TITLED Representation of the Microphysical and Radiative Properties of Ice Clouds in SCMs and GCMs  

SciTech Connect

The broad goal of this research is to improve climate prediction through better representation of cirrus cloud microphysical and radiative properties in global climate models (GCMs). Clouds still represent the greatest source of uncertainty in climate prediction, and the representation of ice clouds is considerably more challenging than liquid water clouds. While about 40% of cloud condensate may be in the form of ice by some estimates, there have been no credible means of representing the ice particle size distribution and mass removal rates from ice clouds in GCMs. Both factors introduce large uncertainties regarding the global net flux, the latter factor alone producing a change of 10 W/m2 in the global net flux due to plausible changes in effective ice particle fallspeed. In addition, the radiative properties of ice crystals themselves are in question. This research provides GCMs with a credible means of representing the full (bimodal) ice particle size distribution (PSD) in ice clouds, including estimates of the small crystal (D < 65 microns) mode of the PSD. It also provides realistic estimates of mass sedimentation rates from ice clouds, which have a strong impact on their ice contents and radiative properties. This can be done through proper analysis of ice cloud microphysical data from ARM and other field campaigns. In addition, this research tests the ice cloud radiation treatment developed under two previous ARM projects by comparing it against laboratory measurements of ice cloud extinction efficiency and by comparing it with explicit theoretical calculations of ice crystal optical properties. The outcome of this project includes two PSD schemes for ice clouds; one appropriate for mid-latitude cirrus clouds and another for tropical anvil cirrus. Cloud temperature and ice water content (IWC) are the inputs for these PSD schemes, which are based on numerous PSD observations. The temperature dependence of the small crystal mode of the PSD for tropical anvils is opposite to that of mid-latitude cirrus, and this results in very different radiative properties for these two types of cirrus at temperatures less than about 50 C for a given ice water path. In addition, the representative PSD fall velocity is strongly influenced by the small crystal mode, and for temperatures less than 52 C, this fall velocity for mid-latitude cirrus is 2-8 times greater than for tropical anvil cirrus. Finally, the treatment of ice cloud optical properties was found to agree with laboratory measurements and exact theory within 15% for any given wavelength, PSD and ice particle shape. This treatment is analytical, formulated in terms of the PSD and ice particle shape properties. It thus provides the means for explicitly coupling the ice cloud microphysical and radiative properties, and can treat any combination of ice particle shape. It is very inexpensive regarding computer time. When these three deliverables were incorporated into the GCM at the National Center for Atmospheric Research (NCAR) under another project, it was found that the sunlight reflected and the amount of upwelling heat absorbed by cirrus clouds depended strongly on the PSD scheme used (i.e. mid-latitude or tropical anvil). This was largely due to the fall velocities associated with the two PSD schemes, although the PSD shape was also important.

Mitchell, David L.

2005-08-08T23:59:59.000Z

231

Top-of-Atmosphere Direct Radiative Effect of Aerosols over the Tropical Oceans from the Clouds and the Earth's Radiant Energy System (CERES) Satellite Instrument  

Science Conference Proceedings (OSTI)

Nine months of the Clouds and the Earth's Radiant Energy System (CERES)/Tropical Rainfall Measuring Mission (TRMM) broadband fluxes combined with the TRMM visible infrared scanner (VIRS) high-resolution imager measurements are used to estimate ...

Norman G. Loeb; Seiji Kato

2002-06-01T23:59:59.000Z

232

Evaluation of Hydrometeor Phase and Ice Properties in Cloud-Resolving Model Simulations of Tropical Deep Convection Using Radiance and Polarization Measurements  

Science Conference Proceedings (OSTI)

Satellite measurements are used to evaluate the glaciation, particle shape, and effective radius in cloud-resolving model simulations of tropical deep convection. Multidirectional polarized reflectances constrain the ice crystal geometry and the ...

Bastiaan van Diedenhoven; Ann M. Fridlind; Andrew S. Ackerman; Brian Cairns

2012-11-01T23:59:59.000Z

233

Effects of Downdrafts and Mesoscale Convective Organization on the Heat and Moisture Budgets of Tropical Cloud Clusters. Part III: Effects of Mesoscale Convective Organization  

Science Conference Proceedings (OSTI)

The effects of mesoscale convective organization on the large-scale heat and moisture budgets of tropical cloud clusters are studied using the GATE Phase III data. Two basic questions concerning the mesoscale effects are addressed: 1) the ...

Ming-Dean Cheng; Michio Yanai

1989-06-01T23:59:59.000Z

234

Effects of Downdrafts and Mesoscale Convective Organization on the Heat and Moisture Budgets of Tropical Cloud Clusters. Part I: A Diagnostic Cumulus Ensemble Model  

Science Conference Proceedings (OSTI)

A diagnostic cumulus ensemble model is developed to study the effects of convective-scale downdrafts and mesoscale convective organization on the heat and moisture budgets of tropical cloud clusters. The model adopts the spectral representation ...

Ming-Dean Cheng

1989-06-01T23:59:59.000Z

235

Warm Core Structures in Organized Cloud Clusters Developing or Not Developing into Tropical Storms Observed by the Advanced Microwave Sounding Unit  

Science Conference Proceedings (OSTI)

The temperature profiles of organized cloud clusters developing or not developing (nondeveloping) into tropical storms (TSs; maximum surface wind >34 kt) over the western North Pacific in 2004 were investigated using Advanced Microwave Sounding ...

Kotaro Bessho; Tetsuo Nakazawa; Shuji Nishimura; Koji Kato

2010-07-01T23:59:59.000Z

236

Multiscale Interactions in the Life Cycle of a Tropical Cyclone Simulated in a Global Cloud-System-Resolving Model. Part II: System-Scale and Mesoscale Processes  

Science Conference Proceedings (OSTI)

The life cycle of Tropical Storm Isobel was simulated reasonably well in the Nonhydrostatic Icosahedral Atmospheric Model (NICAM), a global cloud-system-resolving model. The evolution of the large-scale circulation and the storm-scale structure ...

Hironori Fudeyasu; Yuqing Wang; Masaki Satoh; Tomoe Nasuno; Hiroaki Miura; Wataru Yanase

2010-12-01T23:59:59.000Z

237

Interannual to Diurnal Variations in Tropical and Subtropical Deep Convective Clouds and Convective Overshooting from Seven Years of AMSU-B Measurements  

Science Conference Proceedings (OSTI)

This study surveys interannual to diurnal variations of tropical deep convective clouds and convective overshooting using the Advanced Microwave Sounding Unit B (AMSU-B) aboard the NOAA polar orbiting satellites from 1999 to 2005. The methodology ...

Gang Hong; Georg Heygster; Justus Notholt; Stefan A. Buehler

2008-09-01T23:59:59.000Z

238

Cloud-Resolving Modeling of Tropical Cloud Systems during Phase III of GATE. Part I: Two-Dimensional Experiments  

Science Conference Proceedings (OSTI)

A formal framework is established for the way in which cloud-resolving numerical models are used to investigate the role of precipitating cloud systems in climate and weather forecasting models. Emphasis is on models with periodic lateral ...

Wojciech W. Grabowski; Xiaoqing Wu; Mitchell W. Moncrieff

1996-12-01T23:59:59.000Z

239

An ARSCL-based cloud type climatology from retrievals and it...  

NLE Websites -- All DOE Office Websites (Extended Search)

but misses situations where cirrus clouds overlay low cloud layers. These are mostly prefrontal situations accompanied by mid-tropospheric subsidence and weak southerly winds...

240

Ground-Based Remote Sensing of Cloud Particle Sizes during the 26 November 1991 FIRE II Cirrus Case: Comparisons with In Situ Data  

Science Conference Proceedings (OSTI)

The paper presents the results of retrieving characteristic particle sizes for the November 26 1991 FIRE II case using two methods that utilize ground-based remotes sensors. The size information for the complete vertical depth of the cloud was ...

S. Y. Matrosov; A. J. Heymsfield; J. M. Intrieri; B. W. Orr; J. B. Snider

1995-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Interpretation of AIRS Data in Thin Cirrus Atmospheres Based on a Fast Radiative Transfer Model  

Science Conference Proceedings (OSTI)

A thin cirrus cloud thermal infrared radiative transfer model has been developed for application to cloudy satellite data assimilation. This radiation model was constructed by combining the Optical Path Transmittance (OPTRAN) model, developed for ...

Qing Yue; K. N. Liou; S. C. Ou; B. H. Kahn; P. Yang; G. G. Mace

2007-11-01T23:59:59.000Z

242

A Comparison of Vertical Velocity in Cirrus Obtained from Aircraft and Lidar Divergence Measurements during FIRE  

Science Conference Proceedings (OSTI)

Techniques are presented to obtain vertical velocity in cirrus clouds from in situ aircraft lateral wind measurements and from ground-based remote Doppler lidar measurements. In general, direct measurements of absolute vertical velocity w from ...

I. Gultepe; A. J. Heymsfield; D. H. Lenschow

1990-02-01T23:59:59.000Z

243

Heating Rates in Tropical Anvils  

Science Conference Proceedings (OSTI)

The interaction of infrared and solar radiation with tropical cirrus anvils is addressed. Optical properties of the anvils are inferred from satellite observations and from high-altitude aircraft measurements. An infrared multiple-scattering ...

Thomas P. Ackerman; Kuo-Nan Liou; Francisco P. J. Valero; Leonhard Pfister

1988-05-01T23:59:59.000Z

244

A TRMM-Based Tropical Cyclone Cloud and Precipitation Feature Database  

Science Conference Proceedings (OSTI)

The Tropical Rainfall Measuring Mission (TRMM) satellite has provided invaluable data for tropical cyclone (TC) research since December 1997. The challenge, however, is how to analyze and efficiently utilize all of the information from several ...

Haiyan Jiang; Chuntao Liu; Edward J. Zipser

2011-06-01T23:59:59.000Z

245

Nighttime Multilayered Cloud Detection Using MODIS and ARM Data  

Science Conference Proceedings (OSTI)

This study reports on recent progress toward the discrimination between pixels containing multilayered clouds, specifically optically thin cirrus overlying lower-level water clouds, and those containing single-layered clouds in nighttime Moderate ...

Bryan A. Baum; Richard A. Frey; Gerald G. Mace; Monica K. Harkey; Ping Yang

2003-07-01T23:59:59.000Z

246

Comparison of 30-Day Integrations with and without Cloud-Radiation Interaction  

Science Conference Proceedings (OSTI)

A parameterization package for cloud-radiation interaction is incorporated into a spectral general circulation model (GCM). Fractional cloud amount is predicted quasi-empirically; cloud optical depth is specified for warm clouds and anvil cirrus, ...

C. T. Gordon

1992-07-01T23:59:59.000Z

247

Determination of Effective Emittance and a Radiatively Equivalent Microphysical Model of Cirrus from Ground-Based and Satellite Observations during the International Cirrus Experiment: The 18 October 1989 Case Study  

Science Conference Proceedings (OSTI)

Ground-based observations and satellite data have been compared for the 18 October 1989 case study of the International Cirrus Experiment (ICE) field campaign. They correspond to thin cirrus clouds with infrared emittances in the range 0–0.3. ...

G. Brogniez; J. C. Buriez; V. Giraud; F. Parol; C. Vanbauce

1995-04-01T23:59:59.000Z

248

Finding Tropical Cyclones on a Cloud Computing Cluster: Using Parallel Virtualization for Large-Scale Climate Simulation Analysis  

Science Conference Proceedings (OSTI)

Extensive computing power has been used to tackle issues such as climate changes, fusion energy, and other pressing scientific challenges. These computations produce a tremendous amount of data; however, many of the data analysis programs currently only run a single processor. In this work, we explore the possibility of using the emerging cloud computing platform to parallelize such sequential data analysis tasks. As a proof of concept, we wrap a program for analyzing trends of tropical cyclones in a set of virtual machines (VMs). This approach allows the user to keep their familiar data analysis environment in the VMs, while we provide the coordination and data transfer services to ensure the necessary input and output are directed to the desired locations. This work extensively exercises the networking capability of the cloud computing systems and has revealed a number of weaknesses in the current cloud system software. In our tests, we are able to scale the parallel data analysis job to a modest number of VMs and achieve a speedup that is comparable to running the same analysis task using MPI. However, compared to MPI based parallelization, the cloud-based approach has a number of advantages. The cloud-based approach is more flexible because the VMs can capture arbitrary software dependencies without requiring the user to rewrite their programs. The cloud-based approach is also more resilient to failure; as long as a single VM is running, it can make progress while as soon as one MPI node fails the whole analysis job fails. In short, this initial work demonstrates that a cloud computing system is a viable platform for distributed scientific data analyses traditionally conducted on dedicated supercomputing systems.

Hasenkamp, Daren; Sim, Alexander; Wehner, Michael; Wu, Kesheng

2010-09-30T23:59:59.000Z

249

The Interaction of Clouds and Dry Air in the Eastern Tropical Pacific  

Science Conference Proceedings (OSTI)

Cloud radar observations of eastern Pacific intertropical convergence zone cloud vertical structure are interpreted in light of soundings, 100-km-scale divergence profiles calculated from precipitation radar Doppler velocities, and surface rain ...

Paquita Zuidema; Brian Mapes; Jialin Lin; Chris Fairall; Gary Wick

2006-09-01T23:59:59.000Z

250

Scale Dependence of the Thermodynamic Forcing of Tropical Monsoon Clouds: Results from TRMM Observations  

Science Conference Proceedings (OSTI)

Clouds exert a thermodynamic forcing on the ocean–atmosphere column through latent heating, owing to the production of rain, and through cloud radiative forcing, owing to the absorption of terrestrial infrared energy and the reflection of solar ...

Eric M. Wilcox; V. Ramanathan

2001-04-01T23:59:59.000Z

251

Cloud Microphysical and Radiative Properties Derived from MODIS, VIRS, AVHRR, and GMS Data Over the Tropical Western Pacific  

NLE Websites -- All DOE Office Websites (Extended Search)

Microphysical and Radiative Properties Derived Microphysical and Radiative Properties Derived from MODIS, VIRS, AVHRR, and GMS Data Over the Tropical Western Pacific G. D. Nowicki, M. L. Nordeen, P. W. Heck, D. R. Doelling, and M. M. Khaiyer Analytical Services and Materials, Inc. Hampton, Virginia P. Minnis National Aeronautics and Space Administration Atmospheric Sciences Division Langley Research Center Hampton, Virginia S. Sun-Mack Science Applications International Corporation Hampton, Virginia Introduction Utilization of the geostationary meteorological satellite (GMS) imagery has allowed for the derivation of cloud and radiative properties over the Tropical Western Pacific (TWP) on relatively high spatial and temporal scales. The layered bispectral threshold method (LBTM) has been applied to GMS data

252

Tropical and subtropical cloud transitions in weather and climate prediction models: the GCSS/WGNE Pacific Cross-Section Intercomparison (GPCI)  

SciTech Connect

A model evaluation approach is proposed where weather and climate prediction models are analyzed along a Pacific Ocean cross-section, from the stratocumulus regions off the coast of California, across the shallow convection dominated trade-winds, to the deep convection regions of the ITCZ: the GCSS/WGNE Pacific Cross-section Intercomparison (GPCI). The main goal of GPCI is to evaluate, and help understand and improve the representation of tropical and sub-tropical cloud processes in weather and climate prediction models. In this paper, a detailed analysis of cloud regime transitions along the cross-section from the sub-tropics to the tropics for the season JJA of 1998 is presented. This GPCI study confirms many of the typical weather and climate prediction model problems in the representation of clouds: underestimation of clouds in the stratocumulus regime by most models with the corresponding consequences in terms of shortwave radiation biases; overestimation of clouds by the ECMWF Re-Analysis (ERA40) in the deep tropics (in particular) with the corresponding impact in the outgoing longwave radiation; large spread between the different models in terms of cloud cover, liquid water path and shortwave radiation; significant differences between the models in terms of vertical crosssections of cloud properties (in particular), vertical velocity and relative humidity. An alternative analysis of cloud cover mean statistics is proposed where sharp gradients in cloud cover along the GPCI transect are taken into account. This analysis shows that the negative cloud bias of some models and ERA40 in the stratocumulus regions (as compared to ISCCP) is associated not only with lower values of cloud cover in these regimes, but also with a stratocumulus-to-cumulus transition that occurs too early along the trade-wind Lagrangian trajectory. Histograms of cloud cover along the cross-section differ significantly between models. Some models exhibit a quasi-bimodal structure with cloud cover being either very large (close to 100%) or very small, while other models show a more continuous transition. The ISCCP observations suggest that reality is in-between these two extreme examples. These different patterns reflect the diverse nature of the cloud, boundary layer, and convection parameterizations in the participating weather and climate prediction models.

Teixeira, J.; Cardoso, S.; Bonazzola, M.; Cole, Jason N.; DelGenio, Anthony D.; DeMott, C.; Franklin, A.; Hannay, Cecile; Jakob, Christian; Jiao, Y.; Karlsson, J.; Kitagawa, H.; Koehler, M.; Kuwano-Yoshida, A.; LeDrian, C.; Lock, Adrian; Miller, M.; Marquet, P.; Martins, J.; Mechoso, C. R.; Meijgaard, E. V.; Meinke, I.; Miranda, P.; Mironov, D.; Neggers, Roel; Pan, H. L.; Randall, David A.; Rasch, Philip J.; Rockel, B.; Rossow, William B.; Ritter, B.; Siebesma, A. P.; Soares, P.; Turk, F. J.; Vaillancourt, P.; Von Engeln, A.; Zhao, M.

2011-11-01T23:59:59.000Z

253

TWP-ICE Data from the GEWEX Cloud System Study: Data Integration for Model Evaluation (GCSSDIME)  

DOE Data Explorer (OSTI)

One of the most complete data sets of tropical cirrus and convection observations resulted from the Tropical Warm Pool - International Cloud Experiment (TWP-ICE) in the area around Darwin, Australia. The aim of the experiment is to examine convective cloud systems from their initial stages through the decaying and thin high level cirrus and measure their impact on the environment. The experiment design includes an unprecedented array of soundings and other information to support cloud resolving and other modeling studies as well as a large range of in-situ and remotely sensed observation platforms. A key component of the field campaign is a fleet of aircraft including the Dornier, Dimona, Egrett, Twin Otter, and Proteus. Together, these aircraft collected measurements of cloud properties and the meteorological environment from the planetary boundary layer up to 15 km high. The extensive ground network of cloud sensing radar, lidar and passive instruments are located on a ship and several ground sites throughout the experimental domain. This case study presents data from 19 Jan 2006 to 28 Feb 2006 and covers a region from 25S to 10S latitude and from 125E to 140E longitude.[Copied from http://gcss-dime.giss.nasa.gov/twp-ice/twp-ice.html

254

Understanding the AIRS, ARM, and MODIS cloud products by cross-comparison  

NLE Websites -- All DOE Office Websites (Extended Search)

Understanding the AIRS, ARM, and MODIS cloud products by cross-comparison Understanding the AIRS, ARM, and MODIS cloud products by cross-comparison Kahn, Brian Jet Propulsion Laboratory Eldering, Annmarie Jet Propulsion Laboratory Category: Cloud Properties We present comparisons of the Atmospheric Infrared Sounder (AIRS) operational cloud top height (CTH) to the active surface-based measurements of the Atmospheric Radiation Measurement (ARM) program sites in the tropical Western Pacific. The agreement is found to be consistent to other comparisons of passive IR-derived CTH from other measurement platforms despite the nominal footprint size of 45 km at nadir view. Independent comparisons of CTH to the millimeter-wave cloud radar at Manus Island and the micropulse lidar at Nauru Island indicate that the CTH retrieved by AIRS is statistically significant at the 5% level or less for cirrus cases

255

A Composite and Microphysical Study of Jet Stream Cirrus Over the ARM Site  

NLE Websites -- All DOE Office Websites (Extended Search)

Composite and Microphysical Study of Composite and Microphysical Study of Jet Stream Cirrus Over the ARM Site J. M. Haynes and G. L. Stephens Department of Atmospheric Science Colorado State University Fort Collins, Colorado Introduction Cirrus are known to play an important role in the radiative budget of the earth-atmosphere system. Previous studies have shown that cirrus within strong jet streams account for about 40% to 60% of all cirrus observed in the continental United States during the winter (Menzel et al. 1992). However, the connection between the properties of mid-latitude cirrus clouds and the large-scale flow that supports them is still, to a large degree, unknown. This study seeks to better quantify and understand this relationship through two interrelated investigations.

256

ARM - Publications: Science Team Meeting Documents: Cirrus properties and  

NLE Websites -- All DOE Office Websites (Extended Search)

Cirrus properties and air mean vertical motion retrieval using Cirrus properties and air mean vertical motion retrieval using mm-wavelength Doppler radar moments Deng, Min University of Utah Mace, Gerald University of Utah Vertically pointing millimeter wavelength Doppler radar provides valuable information on upper tropospheric cloud properties and dynamics. We are developing an innovative algorithm to simultaneously retrieve cirrus microphysical parameters and air mean vertical motion by using the three moments of the Doppler spectrum. The technique utilizes a statement that the observed Doppler spectrum is the convolution of a quiet air reflectivity spectrum with the turbulence PDF (probability density function). The set of equations describing the Doppler spectrum moments are inverted using optimal estimation theory to derive estimates of the

257

Mammatus Clouds as a Response to Cloud-Base Radiative Heating  

Science Conference Proceedings (OSTI)

Mammatus clouds are the pouchlike lobes seen hanging from mid- to high-level clouds. They can look quite dramatic, but they are also interesting because they provide clues to what controls anvil cirrus dynamic evolution. Thus far, the most ...

Timothy J. Garrett; Clinton T. Schmidt; Stina Kihlgren; Céline Cornet

2010-12-01T23:59:59.000Z

258

Remote Sensing of Cirrus Radiative Parameters during EUCREX’94. Case Study of 17 April 1994. Part I: Observations  

Science Conference Proceedings (OSTI)

During the intensive European Cloud and Radiation Experiment 1994 (EUCREX’94) conducted off the coast of Brittany (France) over the Atlantic Ocean during April 1994, natural cirrus have been analyzed from in situ and remote sensing measurements. ...

Laurent Sauvage; Pierre H. Flamant; Hélène Chepfer; Gérard Brogniez; Vincent Trouillet; Jacques Pelon; Franck Albers

1999-04-01T23:59:59.000Z

259

The 5–6 December 1991 FIRE IFO II Jet Stream Cirrus Case Study: Possible Influences of Volcanic Aerosols  

Science Conference Proceedings (OSTI)

In presenting an overview of the cirrus clouds comprehensively studied by ground-based and airborne sensors from Coffeyville, Kansas, during the 5–6 December 1992 Project FIRE IFO II case study period, evidence is provided that volcanic aerosols ...

Kenneth Sassen; David O'C. Starr; Gerald G. Mace; Michael R. Poellot; S.H. Melfi; Wynn L. Eberhard; James D. Spinhirne; E.W. Eloranta; Donald E. Hagen; John Hallett

1995-01-01T23:59:59.000Z

260

Seasonal Variability in Clouds and Radiation at the Manus ARM Site  

SciTech Connect

The Atmospheric Radiation Measurement (ARM) program operates three climate observation stations in the tropical western Pacific region. Two of these sites, located on Manus island in Papua New Guinea and on the island republic of Nauru, have been operating for over five years. This data set provides an opportunity to examine variability in tropical cloudiness on a wide range of time scales. The focus of this study is on the annual cycle. The most obvious manifestation of the annual cycle in this region is the oscillation of monsoon convection between Asia and Australia. The impact of the annual cycle on Manus and Nauru is more subtle; however, analysis of radiation and cloud observations from the Manus and Nauru ARM sites reveals links to the annual monsoon cycle. One such link relates to the proximity of Manus to the Maritime Continent, the collection of islands separating the Pacific and Indian oceans. Convection over the large islands in the maritime continent exhibits a distinct annual cycle. Outflow from large-island convection is shown to modulate the cirrus population over Manus. During neutral or cool ENSO periods, convection over Nauru is relatively suppressed. During such periods, Nauru is shown to exhibit an annual cycle in local convective activity. During the inactive season, cirrus are often found near the tropopause over Nauru. These clouds are not formed directly by the outflow from convection. The seasonality and source of these clouds is also examined. Identifying the source of cirrus observed at Manus and Nauru is important because of the potential dependence of cirrus properties on the source of convection.

Mather, Jim H.

2005-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Improvements in Representations of Cloud Microphysics for BBHRP and Models using Data Collected during M-PACE and TWP-ICE  

SciTech Connect

In our research we proposed to use data collected during the 2004 Mixed-Phase Arctic Cloud Experiment (MPACE) and the 2006 Tropical Warm Pool International Cloud Experiment (TWP-ICE) to improve retrievals of ice and mixed-phase clouds, to improve our understanding of how cloud and radiative processes affect cloud life cycles, and to develop and test methods for using ARM data more effectively in model. In particular, we proposed to: 1) use MPACE in-situ data to determine how liquid water fraction and cloud ice and liquid effective radius (r{sub ei} and r{sub ew}) vary with temperature, normalized cloud altitude and other variables for Arctic mixed-phase clouds, and to use these data to evaluate the performance of model parameterization schemes and remote sensing retrieval algorithms; 2) calculate rei and size/shape distributions using TWP-ICE in-situ data, investigate their dependence on cirrus type (oceanic or continental anvils or cirrus not directly traced to convection), and develop and test representations for MICROBASE; 3) conduct fundamental research enhancing our understanding of cloud/radiative interactions, concentrating on effects of small crystals and particle shapes and sizes on radiation; and 4) improve representations of microphysical processes for models (fall-out, effective density, mean scattering properties, rei and rew) and provide them to ARM PIs. In the course of our research, we made substantial progress on all four goals.

Greg M. McFarquhar

2010-02-22T23:59:59.000Z

262

Cirrus 1 | Open Energy Information  

Open Energy Info (EERE)

Cirrus 1 Cirrus 1 Jump to: navigation, search Name Cirrus 1 Facility Cirrus 1 Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Owner Cirrus Wind Energy Developer Wind Tex Energy Energy Purchaser Merchant Location Tahoka TX Coordinates 33.027294°, -101.696782° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":33.027294,"lon":-101.696782,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

263

Improved Measurements of the Ice Water Content in Cirrus Using a Total-Water Probe  

Science Conference Proceedings (OSTI)

This note describes an improved method for the measurement of the ice water content (IWC) of cirrus cloud using a total water content probe. A previous version of this technique assumed that the air in cloud-containing regions was saturated with ...

Philip R. A. Brown; Peter N. Francis

1995-04-01T23:59:59.000Z

264

An Atmospheric Radiation and Cloud Station in the Tropical Western Pacific  

Science Conference Proceedings (OSTI)

The interaction of clouds and radiation is a particularly difficult issue in the study of climate change. Clouds have a large impact on the earth's radiation budget but the range of spatial and temporal scales and the complexity of the physical ...

J. H. Mather; T. P. Ackerman; W. E. Clements; F. J. Barnes; M. D. Ivey; L. D. Hatfield; R. M. Reynolds

1998-04-01T23:59:59.000Z

265

Interannual Variability of the Tropical Radiation Balance and the Role of Extended Cloud Systems  

Science Conference Proceedings (OSTI)

The tropical radiation balance is investigated on an interannual time scale using a five-year(1979–83) dataset obtained from the Nimbus-7 Earth Radiation Budget (ERB) experiment. The study emphasizes the separate contributions to interannual ...

Eric A. Smith; Matthew R. Smith

1987-11-01T23:59:59.000Z

266

Tropical Sensitivity of a Coupled Model to Specified ISCCP Low Clouds  

Science Conference Proceedings (OSTI)

The seasonal cycle of SST observed in the eastern equatorial Pacific is poorly simulated by many ocean–atmosphere coupled GCMs. This deficiency may be partly due to an incorrect prediction of tropical marine stratocumulus (MSc). To explore this ...

C. T. Gordon; A. Rosati; R. Gudgel

2000-07-01T23:59:59.000Z

267

Remote Sounding of High Clouds. V: Infrared Properties and Structures of Tropical Thunderstorm Anvils  

Science Conference Proceedings (OSTI)

The infrared properties and structures of some anvils emanating from local thunderstorms were studied by lidar and infrared radiometry at Darwin, tropical Northern Australia. The anvils were typically from 1 to 2 km deep, at altitudes from 7 to ...

C. M. R. Platt; A. C. Dilley; J. C. Scott; I. J. Barton; G. L. Stephens

1984-09-01T23:59:59.000Z

268

Deep Cumulonimbus Cloud Systems in the Tropics with and without Lightning  

Science Conference Proceedings (OSTI)

The thunderstorm frequency over the oceans during the Global Atmospheric Research Program Atlantic Tropical Experiment is quantified by examination of over 20 000 surface hourly observations from research ships. The overall thunderstorm frequency ...

Edward J. Zipser

1994-08-01T23:59:59.000Z

269

Evidence from Tropical Raindrop Spectra of the Origin of Rain from Stratiform versus Convective Clouds  

Science Conference Proceedings (OSTI)

An analysis of temporal variations in gamma parameters of raindrop spectra is presented utilizing surface-based observations from the Tropical Ocean Global Atmosphere Couple Ocean-Atmosphere Experiment. An observed dramatic change in the N0 ...

Ali Tokay; David A. Short

1996-03-01T23:59:59.000Z

270

Response of ice and liquid water paths of tropical cyclones to global warming simulated by a global nonhydrostatic model with explicit cloud microphysics  

Science Conference Proceedings (OSTI)

Cloud feedback plays a key role in the future climate projection. Using global non-hydrostatic model (GNHM) simulation data for a present-day (CTL) and a warmer (GW) experiment, we estimate the contribution of tropical cyclones (TC) to ice/liquid ...

Yohei Yamada; Masaki Satoh

271

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

Science Conference Proceedings (OSTI)

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 ...

Scott W. Powell; Robert A. Houze Jr.; Anil Kumar; Sally A. McFarlane

2012-09-01T23:59:59.000Z

272

Radar Analysis of a Tropical Convective Boundary Layer with Shallow Cumulus Clouds  

Science Conference Proceedings (OSTI)

A situation of fair weather cloudy convection is examined using a dual Doppler radar, environmental measurements and cloud photogrammetry. The convective layer is characterized by the interaction between the northward monsoon wind at low levels ...

Laurence Eymard

1984-04-01T23:59:59.000Z

273

LASE Measurements of Water Vapor, Aerosol, and Cloud Distributions in Saharan Air Layers and Tropical Disturbances  

Science Conference Proceedings (OSTI)

The Lidar Atmospheric Sensing Experiment (LASE) on board the NASA DC-8 measured high-resolution profiles of water vapor and aerosols, and cloud distributions in 14 flights over the eastern North Atlantic during the NASA African Monsoon ...

Syed Ismail; Richard A. Ferrare; Edward V. Browell; Gao Chen; Bruce Anderson; Susan A. Kooi; Anthony Notari; Carolyn F. Butler; Sharon Burton; Marta Fenn; Jason P. Dunion; Gerry Heymsfield; T. N. Krishnamurti; Mrinal K. Biswas

2010-04-01T23:59:59.000Z

274

Daytime Cycle of Low-Level Clouds and the Tropical Convective Boundary Layer in Southwestern Amazonia  

Science Conference Proceedings (OSTI)

During the wet season in the southwestern Amazon region, daytime water transport out of the atmospheric mixed layer into the deeper atmosphere is shown to depend upon cloud amounts and types and synoptic-scale velocity fields. Interactions among ...

C. Strong; J. D. Fuentes; M. Garstang; A. K. Betts

2005-10-01T23:59:59.000Z

275

Hierarchical Tropical Cloud Systems in an Analog Shallow-Water Model  

Science Conference Proceedings (OSTI)

Recent observations have revealed an hierarchy of cloud clusters and superclusters within the Madden-Julian oscillation of the equatorial troposphere. The authors here report on the results of simulations with a model based on a simple nonlinear ...

Jun-Ichi Yano; James C. McWilliams; Mitchell W. Moncrieff; Kerry A. Emanuel

1995-05-01T23:59:59.000Z

276

Heterogeneous chemistry of atmospheric mineral dust particles and their resulting cloud-nucleation properties  

E-Print Network (OSTI)

ice nucleation in ice and mixed- phase clouds are: 1. WhatWhat is the phase, hygroscopicity, and warm and ice cloudmixed phase clouds, while cirrus clouds are composed of ice

Sullivan, Ryan Christopher

2008-01-01T23:59:59.000Z

277

The 27–28 October 1986 FIRE Cirrus Case Study: Retrieval of Cloud Particle Sizes and Optical Depths from Comparative Analyses of Aircraft and Satellite-based Infrared Measurements  

Science Conference Proceedings (OSTI)

Infrared radiance measurements were acquired from a narrow-field nadir-viewing radiometer based on the NASA ER-2 aircraft during a coincident Landsat 5 overpass on 28 October 1986 as part of the FIRE Cirrus IFO in the vicinity of Lake Michigan. ...

Philip D. Hammer; Francisco P. J. Valero; Stefan Kinne

1991-07-01T23:59:59.000Z

278

The Mysteries of Mammatus Clouds: Observations and Formation Mechanisms  

Science Conference Proceedings (OSTI)

Mammatus clouds are an intriguing enigma of atmospheric fluid dynamics and cloud physics. Most commonly observed on the underside of cumulonimbus anvils, mammatus also occur on the underside of cirrus, cirrocumulus, altocumulus, altostratus, and ...

David M. Schultz; Katharine M. Kanak; Jerry M. Straka; Robert J. Trapp; Brent A. Gordon; Dusan S. Zrni?; George H. Bryan; Adam J. Durant; Timothy J. Garrett; Petra M. Klein; Douglas K. Lilly

2006-10-01T23:59:59.000Z

279

Large-Scale Diurnal Variations of Tropical Cold Cloudiness Based on a Simple Cloud Indexing Method  

Science Conference Proceedings (OSTI)

Diurnal variations of cold cloudiness during a 2-year period (October 1985–September 1987) over the tropical arm covered by Meteosat (from 23°N to 23°S and from 60°E to 60°W) are studied using a simple precipitation index based on infrared data ...

Wassila Thiao; Olli M. Turpeinen

1992-02-01T23:59:59.000Z

280

Parameterization of Ice Cloud Radiative Properties and Its Application to the Potential Climatic Importance of Mixed-Phase Clouds  

Science Conference Proceedings (OSTI)

It is often assumed, in modeling and radiation budget simulation, that clouds below the cirrus level are entirely in the liquid phase. There is substantive evidence from observations that low and middle clouds are often of mixed phase. Using a ...

Zhian Sun; Keith P. Shine

1995-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Anvil characteristics as seen by C-POL during the Tropical Warm Pool International Cloud Experiment (TWP-ICE)  

E-Print Network (OSTI)

The Tropical Pacific Warm Pool International Cloud Experiment (TWP-ICE) took place in Darwin, Australia in early 2006. C-band radar data from this experiment were used to characterize tropical anvil areal coverage, height, and thickness during the month-long field campaign. The morphology, evolution, and longevity of the anvil were analyzed as well as the relationship of the anvil to the rest of the precipitating system. In addition, idealized in-cloud radiative heating profiles were created based on the anvil observations. The anvil was separated into mixed (i.e., echo base below 6 km) and ice only categories. The experiment areal average coverage for both types of anvil was between 4-5% of the radar grid. Ice anvil thickness averaged 2.8 km and mixed anvil thickness averaged 6.7 km. No consistent diurnal signal was seen in the anvil, implying that the life cycle of the parent convection was of first order importance in determining the anvil height, thickness, and area. Areal peaks show that mixed anvil typically formed out of the stratiform region. Peak production in ice anvil usually followed the mixed anvil peak by 1-3 hr. Anvil typically lasted 4-10 hr after the initial convective rain area peak. The TWP-ICE experienced three distinct regimes: the active monsoon, dry monsoon, and break periods. During the entire experiment (except the active monsoon period) there was a strong negative correlation between ice anvil thickness and ice anvil height, a strong positive correlation between ice anvil area and thickness, and a greater variance in ice anvil bottom than ice anvil top. Anvil produced during the active regime had the most dramatic in-cloud radiative response with a maximum cooling of 0.45�° K day-1 at 12 km, a maximum heating of 3�° K day-1 at 9 km, and a secondary maximum heating of 1.2�° K day-1 at 5 km.

Frederick, Kaycee Loretta

2006-12-01T23:59:59.000Z

282

The Role of Clouds, Water Vapor, Circulation, and Boundary Layer Structure in the Sensitivity of the Tropical Climate  

Science Conference Proceedings (OSTI)

The physical mechanisms that affect the tropical sea surface temperature (SST) are investigated using a two-box equilibrium model of the Tropics. One box represents the convecting, warm SST, high humidity region of the Tropics, and the other box ...

Kristin Larson; Dennis L. Hartmann; Stephen A. Klein

1999-08-01T23:59:59.000Z

283

Multiscale Interactions in the Life Cycle of a Tropical Cyclone Simulated in a Global Cloud-System-Resolving Model. Part I: Large-Scale and Storm-Scale Evolutions  

Science Conference Proceedings (OSTI)

The Nonhydrostatic Icosahedral Atmospheric Model (NICAM), a global cloud-system-resolving model, successfully simulated the life cycle of Tropical Storm Isobel that formed over the Timor Sea in the austral summer of 2006. The multiscale ...

Hironori Fudeyasu; Yuqing Wang; Masaki Satoh; Tomoe Nasuno; Hiroaki Miura; Wataru Yanase

2010-12-01T23:59:59.000Z

284

Clouds as Seen by Satellite Sounders (3I) and Imagers (ISCCP). Part III: Spatial Heterogeneity and Radiative Effects  

Science Conference Proceedings (OSTI)

Their relatively good spectral resolution makes infrared sounders very useful for the determination of cloud properties (day and night), and their coarse spatial resolution has less effect on clouds with large spatial extents like cirrus clouds. ...

C. J. Stubenrauch; W. B. Rossow; N. A. Scott; A. Chédin

1999-12-01T23:59:59.000Z

285

Clouds  

NLE Websites -- All DOE Office Websites (Extended Search)

heated by the sun, produces rising columns of air in which the moisture condenses into tall fleecy white clouds At night, when the sky is clear, the earth cools to give those...

286

Testing ice microphysics parameterizations in the NCAR Community Atmospheric Model Version 3 using Tropical Warm Pool–International Cloud Experiment data  

SciTech Connect

Cloud properties have been simulated with a new double-moment microphysics scheme under the framework of the single column version of NCAR CAM3. For comparisons, the same simulation was made with the standard single-moment microphysics scheme of CAM3. Results from both simulations were compared favorably with observations during the Tropical Warm Pool- International Cloud Experiment by US Department of Energy Atmospheric Radiation Program in terms of the temporal variation and vertical distribution of cloud fraction and cloud condensate. Major differences between the two simulations are in the magnitude and distribution of ice water content within the mixed-phase cloud during the monsoon period, though the total frozen water (snow plus ice) content is similar. The ice mass content in the mixed-phase cloud from the new scheme is larger than that from the standard scheme, and extends 2 km further downward, which are closer to observations. The dependence of the frozen water mass fraction in total condensate on temperature from the new scheme is also closer to available observations. Outgoing longwave radiation (OLR) at the top of the atmosphere (TOA) from the simulation with the new scheme is in general larger than that with the standard scheme, while the surface downward longwave radiation is similar. Sensitivity tests suggest that different treatments of the ice effective radius contribute significantly to the difference in the TOA OLR in addition to cloud water path. The deep convection process affects both TOA OLR and surface downward longwave radiation. The over-frequently-triggered deep convention process in the model is not the only mechanism for the excess middle and high level clouds. Further evaluation especially for ice cloud properties based on in-situ data is needed.

Wang, Weiguo; Liu, Xiaohong; Xie, Shaocheng; Boyle, James; McFarlane, Sally A.

2009-07-23T23:59:59.000Z

287

Measurements of the Ice Water Content in Cirrus Using an Evaporative Technique  

Science Conference Proceedings (OSTI)

A technique for the measurement of the ice water content (IWC) of cirrus clouds is described. The IWC is obtained by the measurement of the total water content (TWC) and the subtraction of the saturation specific humidity with respect to ice at ...

Philip R. A. Brown

1993-08-01T23:59:59.000Z

288

Measuring Crystal Size in Cirrus Using 35- and 94-GHz Radars  

Science Conference Proceedings (OSTI)

Results are presented from a case study in which coincident 35- and 94-GHz radars located at Chilbolton, England, were used to measure crystal size in cirrus clouds. In the presence of larger crystals the 94-GHz radar scatters sufficiently beyond ...

Robin J. Hogan; Anthony J. Illingworth; Henri Sauvageot

2000-01-01T23:59:59.000Z

289

A Climatology of Tropical Anvil and Its Relationship to the Large-Scale Circulation  

E-Print Network (OSTI)

This dissertation uses multiple tools to investigate tropical anvil, i.e., thick, non-precipitating cloud associated with deep convection with the main objectives to provide a climatology of tropics-wide anvil properties and a better understanding of anvil formation, and to provide a more realistic assessment of the radiative impact of tropical anvil on the large-scale circulation. Based on 10 years (1998-2007) of observations, anvil observed by the Tropical Rainfall Measuring Mission (TRMM) Precipitation (PR) shows significant geographical variations, which can be linked to variations in the parent convection. Strong upper level wind shear appears to assist the generation of anvil and may further explain the different anvil statistics over land and ocean. Variations in the large-scale environment appear to play a more important role in anvil production in regions where convection regularly attains heights greater than 7 km. For regions where convection is less deep, variations in the depth of the convection and the large-scale environment likely contribute more equally to anvil generation. Anvil radiative heating profiles are estimated by extrapolating millimeter cloud radar (MMCR) radiative properties from Manus to the 10-year TRMM PR record. When the unconditional anvil areal coverage is taken into account, the anvil radiative heating becomes quite weak, increasing the PR latent heating profile by less than 1 percent at mid and upper levels. Stratiform rain and cirrus radiative heating contributions increase the upper level latent heating by 12 percent. This tropical radiative heating only slightly enhances the latent heating driven model response throughout the tropics, but more significantly over the East Pacific. These modest circulation changes suggest that previous studies may have overemphasized the importance of radiative heating in terms of Walker and Hadley circulation variations. Further, the relationship of cloud radiative heating to latent heating needs to be taken into account for more realistic studies of cloud radiative forcing on the large-scale circulation.

Li, Wei

2009-12-01T23:59:59.000Z

290

Initialization of a Cloud-Resolving Model with Airborne Doppler Radar Observations of an Oceanic Tropical Convective System  

Science Conference Proceedings (OSTI)

Doppler radar–derived fields of wind and reflectivity, retrieved temperature perturbations, estimated water vapor, and cloud water contents are used to initialize a nonhydrostatic cloud-resolving model. Airborne Doppler data collected in a ...

Soline Bielli; Frank Roux

1999-06-01T23:59:59.000Z

291

On the Climatology of Upper-Layer Clouds  

Science Conference Proceedings (OSTI)

Unique data obtained from a regular aircraft sounding network that operated in the Soviet Union from 1957 through 1963 were used to estimate the potential accuracy of the cirrus cloud cover climatology based on routine ground-based weather ...

Ilia P. Mazin; Svetlana N. Burkovskaya; Elvira T. Ivanova

1993-09-01T23:59:59.000Z

292

Retrieving Properties of Thin Clouds from Solar Aureole Measurements  

Science Conference Proceedings (OSTI)

This paper describes a newly designed Sun and Aureole Measurement (SAM) aureolegraph and the first results obtained with this instrument. SAM measurements of solar aureoles produced by cirrus and cumulus clouds were taken at the Atmospheric ...

J. G. DeVore; A. T. Stair; A. LePage; D. Rall; J. Atkinson; D. Villanucci; S. A. Rappaport; P. C. Joss; R. A. McClatchey

2009-12-01T23:59:59.000Z

293

Identification of Small Ice Cloud Particles Using Passive Radiometric Observations  

Science Conference Proceedings (OSTI)

There is currently significant uncertainty about the extent to which cirrus clouds are composed of “small” ice crystals smaller than about 20-?m effective radius. This is due in part to concerns that in situ measurements from aircraft are plagued ...

Steven J. Cooper; Timothy J. Garrett

2010-11-01T23:59:59.000Z

294

arm_stm_2007_revercomb_poster_cloud.ppt  

NLE Websites -- All DOE Office Websites (Extended Search)

Assessment Part 2: Cirrus Radiative Flux Study Using RadarLidarAERI Derived Cloud Properties David Tobin, Lori Borg, David Turner, Robert Holz, Daniel DeSlover, Hank Revercomb,...

295

Marine Stratocumulus Cloud Fields off the Coast of Southern California Observed Using LANDSAT Imagery. Part II: Textural Analysis  

Science Conference Proceedings (OSTI)

Statistical measures of the spatial distributions of gray levels (cloud reflectivities) are determined for LANDSAT Multispectral Scanner digital data. Textural properties for twelve stratocumulus cloud fields, seven cumulus fields, and two cirrus ...

R. M. Welch; S. K. Sengupta; K. S. Kuo

1988-04-01T23:59:59.000Z

296

A Parameterization of the Visible Extinction Coefficient of Ice Clouds in Terms of the Ice/Water Content  

Science Conference Proceedings (OSTI)

This article describes a parameterization of the visible extinction coefficient of cirrus and frontal ice cloud in terms of the ice/water content. The parameterization is based on the discovery that the ice cloud particle size spectra from a ...

C. Martin R. Platt

1997-08-01T23:59:59.000Z

297

ARM tropical pacific experiment (ATPEX): Role of cloud, water vapor and convection feedbacks in the coupled ocean/atmosphere system  

SciTech Connect

We have initiated studies that include radiation model validation, improved treatment of the three-dimensional structure of cloud-radiation interactions, and sensitivity runs that will unravel the role of cloud-convection-radiation interactions in the Pacific Sear Surface Temperatures and the overlying Walker and Hadley circulation. The research program is divided into three phases: (1) radiation, (2) cloud parameterization issues; (3) feedback and ocean-atmosphere interactions.

Ramanathan, V.; Barnett, T.P.

1992-03-05T23:59:59.000Z

298

Global ice cloud observations: radiative properties and statistics from moderate-resolution imaging spectroradiometer measurements  

E-Print Network (OSTI)

Ice clouds occur quite frequently, yet so much about these clouds is unknown. In recent years, numerous investigations and field campaigns have been focused on the study of ice clouds, all with the ultimate goal of gaining a better understanding of microphysical and optical properties, as well as determining the radiative impact. Perhaps one of the most recognized instruments used for such research is the Moderate-resolution Imaging Spectroradiometer (MODIS), carried aboard the NASA EOS satellites Terra and Aqua. The present research aims to support ongoing efforts in the field of ice cloud research by use of observations obtained from Terra and Aqua MODIS. First, a technique is developed to infer ice cloud optical depth from the MODIS cirrus reflectance parameter. This technique is based on a previous method developed by Meyer et al. (2004). The applicability of the algorithm is demonstrated with retrievals from level-2 and -3 MODIS data. The technique is also evaluated with the operational MODIS cloud retrieval product and a method based on airborne ice cloud observations. From this technique, an archive of daily optical depth retrievals is constructed. Using simple statistics, the global spatial and temporal distributions of ice clouds are determined. Research has found that Aqua MODIS observes more frequent ice clouds and larger optical depths and ice water paths than does Terra MODIS. Finally, an analysis of the time series of daily optical depth values revealed that ice clouds at high latitudes, which are most likely associated with synoptic scale weather sytems, persist long enough to move with the upper level winds. Tropical ice clouds, however, dissipate more rapidly, and are in all likelihood associated with deep convective cells.

Meyer, Kerry Glynne

2007-08-01T23:59:59.000Z

299

Observational Analysis of Tropical Cyclogenesis in the Western North Pacific. Part I: Structural Evolution of Cloud Clusters  

Science Conference Proceedings (OSTI)

This paper is the first of a two-part series summarizing recent attempts to advance omit understanding of the physical processes associated with tropical cyclone formation in the western North Pacific. A combination of rawinsonde composite and ...

Cheng Shang Lee

1989-08-01T23:59:59.000Z

300

Squall Lines and Convectively Coupled Gravity Waves in the Tropics: Why Do Most Cloud Systems Propagate Westward?  

Science Conference Proceedings (OSTI)

The coupling between tropical convection and zonally propagating gravity waves is assessed through Fourier analysis of high-resolution (3-hourly, 0.5°) satellite rainfall data. Results show the familiar enhancement in power along the dispersion ...

Stefan N. Tulich; George N. Kiladis

2012-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Boundary Layer Depth, Entrainment, and Decoupling in the Cloud-Capped Subtropical and Tropical Marine Boundary Layer  

Science Conference Proceedings (OSTI)

Estimates of marine boundary layer (MBL) depth and degree of decoupling for two regions of the subtropical and tropical east Pacific are presented using satellite observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the ...

Robert Wood; Christopher S. Bretherton

2004-09-01T23:59:59.000Z

302

Sea Surface Temperature and Large-Scale Circulation Influences on Tropical Greenhouse Effect and Cloud Radiative Forcing  

Science Conference Proceedings (OSTI)

Two independent sets of meteorological reanalyses are used to investigate relationships between the tropical sea surface temperature (SST) and the large-scale vertical motion of the atmosphere for spatial and seasonal variations, as well as for ...

S. Bony; K-M. Lau; Y. C. Sud

1997-08-01T23:59:59.000Z

303

Development of a Detailed Microphysics Cirrus Model Tracking Aerosol Particles’ Histories for Interpretation of the Recent INCA Campaign  

Science Conference Proceedings (OSTI)

Cirrus clouds play an important role in the earth’s energy balance. To quantify their impact, information is needed on their microstructure and more precisely on the number and size of the ice crystals. With the anthropogenic activity, more and ...

Marie Monier; Wolfram Wobrock; Jean-François Gayet; Andrea Flossmann

2006-02-01T23:59:59.000Z

304

The Occurrence of Particle Size Distribution Bimodality in Midlatitude Cirrus as Inferred from Ground-Based Remote Sensing Data  

Science Conference Proceedings (OSTI)

Data collected in midlatitude cirrus clouds by instruments on jet aircraft typically show particle size distributions that have distinct distribution modes in both the 10–30-?m maximum dimension (D) size range and the 200–300-?m D size range or ...

Yang Zhao; Gerald G. Mace; Jennifer M. Comstock

2011-06-01T23:59:59.000Z

305

The Diurnal Cycle of the Boundary Layer, Convection, Clouds, and Surface Radiation in a Coastal Monsoon Environment (Darwin Australia)  

SciTech Connect

The diurnal variation of convection and associated cloud and radiative properties remains a significant issue in global NWP and climate models. This study analyzes observed diurnal variability of convection in a coastal monsoonal environment examining the interaction of convective rain clouds, their associated cloud properties, and the impact on the surface radiation and corresponding boundary layer structure during periods where convection is suppressed or active on the large scale. The analysis uses data from the Tropical Warm Pool International Cloud Experiment (TWP-ICE) as well as routine measurements from the Australian Bureau of Meteorology and the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program. Both active monsoonal and large-scale suppressed (buildup and break) conditions are examined and demonstrate that the diurnal variation of rainfall is much larger during the break periods and the spatial distribution of rainfall is very different between the monsoon and break regimes. During the active monsoon the total net radiative input to the surface is decreased by more than 3 times the amount than during the break regime - this total radiative cloud forcing is found to be dominated by the shortwave (SW) cloud effects because of the much larger optical thicknesses and persistence of long-lasting anvils and cirrus cloud decks associated with the monsoon regime. These differences in monsoon versus break surface radiative energy contribute to low-level air temperature differences in the boundary layer over the land surfaces.

May, Peter T.; Long, Charles N.; Protat, Alain

2012-08-01T23:59:59.000Z

306

Toward an understanding of vertical momentum transports in cloud system resolving model simulations of multiscale tropical convection  

Science Conference Proceedings (OSTI)

This study examines the characteristics of convective momentum transport (CMT) and gravity wave momentum transport (GWMT) in two-dimensional cloud-system resolving model simulations, including the relationships between the two transports. A linear ...

Tiffany A. Shaw; Todd P. Lane

307

Spatial and Temporal Scales of Precipitating Tropical Cloud Systems in Satellite Imagery and the NCAR CCM3  

Science Conference Proceedings (OSTI)

Testing general circulation model parameterizations against observations is traditionally done by comparing simulated and observed, time-averaged quantities, such as monthly mean cloud cover, evaluated on a stationary grid. This approach ignores ...

Eric M. Wilcox

2003-11-01T23:59:59.000Z

308

Impacts of Nucleating Aerosol on Florida Storms. Part I: Mesoscale Simulations  

Science Conference Proceedings (OSTI)

Toward the end of the Cirrus Regional Study of Tropical Anvils and Cirrus Layer–Florida Area Cirrus Experiment (CRYSTAL–FACE) field campaign held during July 2002, high concentrations of Saharan dust, which can serve as cloud condensation nuclei (...

Susan C. van den Heever; Gustavo G. Carrió; William R. Cotton; Paul J. DeMott; Anthony J. Prenni

2006-07-01T23:59:59.000Z

309

Comparison of CALIPSO-Like, LaRC, and MODIS Retrievals of Ice-Cloud Properties over SIRTA in France and Florida during CRYSTAL-FACE  

Science Conference Proceedings (OSTI)

This study compares cirrus-cloud properties and, in particular, particle effective radius retrieved by a Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO)-like method with two similar methods using Moderate-Resolution ...

M. Chiriaco; H. Chepfer; P. Minnis; M. Haeffelin; S. Platnick; D. Baumgardner; P. Dubuisson; M. McGill; V. Noël; J. Pelon; D. Spangenberg; S. Sun-Mack; G. Wind

2007-03-01T23:59:59.000Z

310

Aggregation of Ice Crystals in Cirrus  

Science Conference Proceedings (OSTI)

Results are given from analysis of the aggregation of thick plate, columnar, and bullet rosette ice crystals in cirrus. Data were obtained from PMS 2D-C images, oil coated slides, and aircraft meteorological measurements. Crystal size ranged from ...

Masahiro Kajikawa; Andrew J. Heymsfield

1989-10-01T23:59:59.000Z

311

Contrails and Induced Cirrus: Optics and Radiation  

Science Conference Proceedings (OSTI)

This paper summarizes the assessment of the current state of knowledge, areas of uncertainties, and recommendations for future efforts, regarding the optical and radiative properties of contrails and contrail cirrus, which have been reported in ...

Ping Yang; Gang Hong; Andrew E. Dessler; Steve S. C. Ou; Kuo-Nan Liou; Patrick Minnis; Harshvardhan

2010-04-01T23:59:59.000Z

312

On the Wave Spectrum Generated by Tropical Heating  

Science Conference Proceedings (OSTI)

Convective heating profiles are computed from one month of rainfall rate and cloud-top height measurements using global Tropical Rainfall Measuring Mission and infrared cloud-top products. Estimates of the tropical wave response to this heating ...

David A. Ortland; M. Joan Alexander; Alison W. Grimsdell

2011-09-01T23:59:59.000Z

313

TC_CLOUD_REGIME.cdr  

NLE Websites -- All DOE Office Websites (Extended Search)

Tropical cloud properties as a function of regime Regimes? Monsoon versus Break * Different synoptic vertical velocity profiles - Changes convective inhibition, corresponding...

314

Upper Tropospheric Waves in the Tropics. Part II. Association with Clouds in the Wavenumber-Frequency Domain  

Science Conference Proceedings (OSTI)

The relationship between the large-scale transient wave disturbances at the 200 mb level and the associated cloud field is studied in the latitude belt 20°S to 40°N based on wind and satellite-measured brightness data for the period June–August ...

Abraham Zangvil; Michio Yanai

1981-05-01T23:59:59.000Z

315

Cirrus Infrared Parameters and Shortwave Reflectance Relations from Observations  

Science Conference Proceedings (OSTI)

A summary of experimental observations and analysis of cirrus from high-altitude aircraft remote sensing is presented. The vertical distribution of cirrus optical and infrared cross-section parameters and the relative effective emittance and ...

James D. Spinhirne; William D. Hart; Dennis L. Hlavka

1996-05-01T23:59:59.000Z

316

Remote Sounding of High Clouds. III: Monte Carlo Calculations of Multiple-Scattered Lidar Returns  

Science Conference Proceedings (OSTI)

Monte Carlo calculations of multiple-scattered contributions to the total energy received in a lidar beam have been made for a representative cirrus ice-cloud scattering phase function. The phase function is varied arbitrarily near the back ...

C. M. R. Platt

1981-01-01T23:59:59.000Z

317

Microwave Radiative Transfer through Clouds Composed of Realistically Shaped Ice Crystals. Part I. Single Scattering Properties  

Science Conference Proceedings (OSTI)

This paper presents the results of a detailed study of the microwave single scattering properties of ice crystals expected in cirrus clouds. The discrete dipole approximation is used to compute scattering quantities of particles ranging in size ...

K. Franklin Evans; Graeme L. Stephens

1995-06-01T23:59:59.000Z

318

Coupling between Gravity Waves and Tropical Convection at Mesoscales  

Science Conference Proceedings (OSTI)

An idealized cloud-system-resolving model simulation is used to examine the coupling between a tropical cloud population and the mesoscale gravity waves that it generates. Spectral analyses of the cloud and gravity wave fields identify a clear ...

Todd P. Lane; Fuqing Zhang

2011-11-01T23:59:59.000Z

319

Retrieval of cloud properties using CALIPSO Imaging Infrared Radiometer. Part II: effective diameter and ice water path  

Science Conference Proceedings (OSTI)

The paper describes the version 3 Level 2 operational analysis of the Imaging Infrared Radiometer (IIR) data collected in the framework of the CALIPSO mission to retrieve cirrus cloud effective diameter and ice water path in synergy with the ...

Anne Garnier; Jacques Pelon; Philippe Dubuisson; Ping Yang; Michaël Faivre; Olivier Chomette; Nicolas Pascal; Pat Lucker; Tim Murray

320

Evaluation of Several A-Train Ice Cloud Retrieval Products with In Situ Measurements Collected during the SPARTICUS Campaign  

Science Conference Proceedings (OSTI)

In this study several ice cloud retrieval products that utilize active and passive A-Train measurements are evaluated using in situ data collected during the Small Particles in Cirrus (SPARTICUS) field campaign. The retrieval datasets include ice ...

Min Deng; Gerald G. Mace; Zhien Wang; R. Paul Lawson

2013-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Impact of Ice Crystal Roughness on Satellite Retrieved Cloud Properties  

NLE Websites -- All DOE Office Websites (Extended Search)

Ice Crystal Roughness on Satellite Retrieved Cloud Properties Ice Crystal Roughness on Satellite Retrieved Cloud Properties P. Minnis 1 , P. W. Heck 2 , R. F. Arduini 3 , R. Palikonda 3 , J. K. Ayers 3 , M. M. Khaiyer 3 , P. Yang 4 , Y. Xie 4 3 Science Systems & Applications, Inc. Hampton, VA 1 NASA Langley Research Center Hampton, VA Current Cirrus Models Inadequate Cirrus cloud optical depths Ï„ (heights z e ) are often over (under) estimated when derived from solar reflectances. In situ data suggest smaller asymmetry factors, g, than used in most retrieval models. Multi-angle measurements point to smoother phase functions than for solid, smooth xtals. Calculations show that solid crystals with roughened facets or embedded bubbles --both observed in real cirrus particles-- yield smoother phase functions & smaller g

322

Assessment of Uncertainty in Cloud Radiative Effects and Heating Rates through Retrieval Algorithm Differences: Analysis using 3-years of ARM data at Darwin, Australia  

SciTech Connect

Ground-based radar and lidar observations obtained at the Department of Energy’s Atmospheric Radiation Measurement Program’s Tropical Western Pacific site located in Darwin, Australia are used to retrieve ice cloud properties in anvil and cirrus clouds. Cloud microphysical properties derived from four different retrieval algorithms (two radar-lidar and two radar only algorithms) are compared by examining mean profiles and probability density functions of effective radius (Re), ice water content (IWC), extinction, ice number concentration, ice crystal fall speed, and vertical air velocity. Retrieval algorithm uncertainty is quantified using radiative flux closure exercises. The effect of uncertainty in retrieved quantities on the cloud radiative effect and radiative heating rates are presented. Our analysis shows that IWC compares well among algorithms, but Re shows significant discrepancies, which is attributed primarily to assumptions of particle shape. Uncertainty in Re and IWC translates into sometimes-large differences in cloud radiative effect (CRE) though the majority of cases have a CRE difference of roughly 10 W m-2 on average. These differences, which we believe are primarily driven by the uncertainty in Re, can cause up to 2 K/day difference in the radiative heating rates between algorithms.

Comstock, Jennifer M.; Protat, Alain; McFarlane, Sally A.; Delanoe, Julien; Deng, Min

2013-05-22T23:59:59.000Z

323

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

NLE Websites -- All DOE Office Websites (Extended Search)

and shapes. The vertical variation of ice crystal size can alter the radiative heatingcooling profiles in cirrus cloudy atmospheres and hence is an important component in the...

324

Effects of Radiation and Turbulence on the Diabatic Heating and Water Budget of the Stratiform Region of a Tropical Cloud Cluster  

Science Conference Proceedings (OSTI)

A two-dimensional, kinematic model, incorporating ice- and water-cloud microphysics, visible and infrared radiation, and convective adjustment, is used to diagnose the thermodynamic, water vapor, and hydrometeor fields of the stratiform clouds ...

Dean D. Churchill; Robert A. Houze Jr.

1991-04-01T23:59:59.000Z

325

A Study of the Probability of Clear Line of Sight through Single-Layer Cumulus Cloud Fields in the Tropical Western Pacific  

Science Conference Proceedings (OSTI)

The plane-parallel horizontal (PPH) hypothesis used to approximate clouds in GCMs neglects three-dimensional cloud effects. Such effects can amount to as much as 20 W m?2 in longwave radiation. Several investigators have proposed accounting for ...

Patrick C. Taylor; Robert G. Ellingson

2008-11-01T23:59:59.000Z

326

Heat, Moisture, and Momentum Budgets of Isolated Deep Midlatitude and Tropical Convective Clouds as Diagnosed from Three-Dimensional Model Output. Part I: Control Experiments  

Science Conference Proceedings (OSTI)

This project uses a three-dimensional anelastic cloud model with a simple ice phase parameterization to evaluate the feedback between isolated deep convective clouds and their near surroundings. The horizontal Reynolds averaging approach of ...

Robert E. Schlesinger

1994-12-01T23:59:59.000Z

327

The Relationship between Satellite Measured Convective Bursts and Tropical Cyclone Intensification  

Science Conference Proceedings (OSTI)

The relationship between the mean temperature of the top of the cloud canopies and the future maximum winds of Atlantic Ocean tropical cyclones is analyzed. The area-average cloud top temperatures from 309 observations of 12 tropical cyclones ...

Joseph Steranka; Edward B. Rodgers; R. Cecil Gentry

1986-08-01T23:59:59.000Z

328

Examination of Coupling between an Upper-Tropospheric Cloud System and Synoptic-Scale Dynamics Diagnosed from Wind Profiler and Radiosonde Data  

Science Conference Proceedings (OSTI)

The evolution of synoptic-scale dynamics associated with a middle and upper tropospheric cloud event that occurred on 26 November 1991 is examined. The case under consideration occurred during the FIRE Cirrus-II Intensive Field Observing Period ...

Gerald G. Mace; David O'C. Starr; Thomas P. Ackerman; Patrick Minnis

1995-12-01T23:59:59.000Z

329

Tropical Plumes over Eastern North Africa as a Source of Rain in the Middle East  

Science Conference Proceedings (OSTI)

Tropical plumes (TPs) reflect tropical–extratropical interaction associated with the transport of moisture from the Tropics to extratropical latitudes. They are observed in satellite images as continuous narrow cloud bands ahead of upper-level ...

Shira Rubin; Baruch Ziv; Nathan Paldor

2007-12-01T23:59:59.000Z

330

Parameterizing Size Distribution in Ice Clouds  

SciTech Connect

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 µm) 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 µm), 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 µm wavelength relative to 11 µm wavelength due to the process of wave resonance or photon tunneling more active at 12 µm. This makes the 12/11 µm absorption optical depth ratio (or equivalently the 12/11 µm 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.

DeSlover, Daniel; Mitchell, David L.

2009-09-25T23:59:59.000Z

331

ARM tropical pacific experiment (ATPEX): Role of cloud, water vapor and convection feedbacks in the coupled ocean/atmosphere system. Progress report, September 1, 1991--August 31, 1992  

SciTech Connect

We have initiated studies that include radiation model validation, improved treatment of the three-dimensional structure of cloud-radiation interactions, and sensitivity runs that will unravel the role of cloud-convection-radiation interactions in the Pacific Sear Surface Temperatures and the overlying Walker and Hadley circulation. The research program is divided into three phases: (1) radiation, (2) cloud parameterization issues; (3) feedback and ocean-atmosphere interactions.

Ramanathan, V.; Barnett, T.P.

1992-03-05T23:59:59.000Z

332

The Significance of Cloud–Radiative Forcing to the General Circulation on Climate Time Scales—A Satellite Interpretation  

Science Conference Proceedings (OSTI)

Cloud–radiative forcing calculations based on Nimbus-7 radiation budget and cloudiness measurements reveal that cloud-induced longwave (LW) warming (cloud greenhouse influence) is dominant over the tropics, whereas cloud-induced shortwave (SW) ...

Byung-Ju Sohn; Eric A. Smith

1992-05-01T23:59:59.000Z

333

Physical Characterization of Tropical Oceanic Convection Observed in KWAJEX  

Science Conference Proceedings (OSTI)

The Tropical Rainfall Measuring Mission (TRMM) Kwajalein Experiment (KWAJEX) was designed to obtain an empirical physical characterization of precipitating convective clouds over the tropical ocean. Coordinated datasets were collected by three ...

Sandra E. Yuter; Robert A. Houze Jr.; Eric A. Smith; Thomas T. Wilheit; Edward Zipser

2005-04-01T23:59:59.000Z

334

Aerosol Effects on Microstructure and Intensity of Tropical Cyclones  

Science Conference Proceedings (OSTI)

Improving the forecasts of the intensity of tropical cyclones (TCs) remains a major challenge. One possibility for improvement is consideration of the effects that aerosols have on tropical clouds and cyclones. The authors have been pursuing this under ...

Daniel Rosenfeld; William L. Woodley; Alexander Khain; William R. Cotton; Gustavo Carrió; Isaac Ginis; Joseph H. Golden

2012-07-01T23:59:59.000Z

335

Sensitivity of Tropical Cyclone Rainbands to Ice-Phase Microphysics  

Science Conference Proceedings (OSTI)

A high-resolution tropical cyclone model with explicit cloud microphysics has been used to investigate the dynamics and energetics of tropical cyclone rainbands. As a first step, the model rainbands have been qualitatively compared with observed ...

Charmaine N. Franklin; Greg J. Holland; Peter T. May

2005-08-01T23:59:59.000Z

336

A 39-Yr Survey of Cloud Changes from Land Stations Worldwide 1971–2009: Long-Term Trends, Relation to Aerosols, and Expansion of the Tropical Belt  

Science Conference Proceedings (OSTI)

An archive of land-based, surface-observed cloud reports has been updated and now spans 39 years from 1971 through 2009. Cloud-type information at weather stations is available in individual reports or in long-term, seasonal, and monthly averages. ...

Ryan Eastman; Stephen G. Warren

2013-02-01T23:59:59.000Z

337

A Simple Multicloud Parameterization for Convectively Coupled Tropical Waves. Part II: Nonlinear Simulations  

Science Conference Proceedings (OSTI)

Observations in the Tropics point to the important role of three cloud types, congestus, stratiform, and deep convective clouds, besides ubiquitous shallow boundary layer clouds for both the climatology and large-scale organized anomalies such as ...

Boualem Khouider; Andrew J. Majda

2007-02-01T23:59:59.000Z

338

Improvements of an Ice-Phase Microphysics Parameterization for Use in Numerical Simulations of Tropical Convection  

Science Conference Proceedings (OSTI)

It is important to properly simulate the extent and ice water content of tropical anvil clouds in numerical models that explicitly include cloud formation because of the significant effects that these clouds have on the radiation budget. For this ...

Steven K. Krueger; Qiang Fu; K. N. Liou; Hung-Neng S. Chin

1995-01-01T23:59:59.000Z

339

Origin of Lapse Rate Changes in the Upper Tropical Troposphere  

Science Conference Proceedings (OSTI)

Vertical motions in clouds arise from a variety of thermodynamic processes, including latent heat release, evaporative cooling, melting, and cloud radiative heating. In the Tropics, the net upward vertical mass flux from convective systems should ...

Ian Folkins

2002-03-01T23:59:59.000Z

340

Insights into Cloud-Top Height and Dynamics from the Seasonal Cycle of Cloud-Top Heights Observed by MISR in the West Pacific Region  

Science Conference Proceedings (OSTI)

The connection between environmental stability and the height of tropical deep convective clouds is analyzed using stereo cloud height data from the Multiangle Imaging Spectroradiometer (MISR), focusing on the seasonal cycle of clouds over the ...

Jung Hyo Chae; Steven C. Sherwood

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Final Report for Research Conducted at The Scripps Institution of Oceanography, University of California San Diego from 2/2002 to 8/2003 for ''Aerosol and Cloud-Field Radiative Effects in the Tropical Western Pacific: Analyses and General Circulation Model Parameterizations''  

SciTech Connect

OAK-B135 Final report from the University of California San Diego for an ongoing research project that was moved to Brookhaven National Laboratory where proposed work will be completed. The research uses measurements made by the Atmospheric Radiation Measurement (ARM) Program to quantify the effects of aerosols and clouds on the Earth's energy balance in the climatically important Tropical Western Pacific.

Vogelmann, A. M.

2004-01-27T23:59:59.000Z

342

Application of Surface-Adjusted GOES Low-Level Cloud-Drift Winds in the Environment of Atlantic Tropical Cyclones. Part II: Integration into Surface Wind Analyses  

Science Conference Proceedings (OSTI)

The Cooperative Institute for Meteorological Satellite Studies at the University of Wisconsin—Madison recently (1997 season) began providing real-time Geostationary Operational Environmental Satellite (GOES) low-level cloud-drift winds in the ...

Jason P. Dunion; Samuel H. Houston; Christopher S. Velden; Mark D. Powell

2002-05-01T23:59:59.000Z

343

A Parametric Radiative Forcing Model for Contrail Cirrus  

Science Conference Proceedings (OSTI)

A new parameterized analytical model is presented to compute the instantaneous radiative forcing (RF) at the top of the atmosphere (TOA) produced by an additional thin contrail cirrus layer (called “contrail” below). The model calculates the RF ...

U. Schumann; B. Mayer; K. Graf; H. Mannstein

2012-07-01T23:59:59.000Z

344

Effects of Downdrafts and Mesoscale Convective Organization on the Heat and Moisture Budgets of Tropical Cloud Clusters. Part II: Effects of Convective-Scale Downdrafts  

Science Conference Proceedings (OSTI)

The diagnostic cumulus ensemble model presented in Part I of this paper is applied to the data taken during Phase III of the GARP Tropical Atlantic Experiment (GATE) to examine the effects of convective-scale downdrafts on the large-scale heat ...

Ming-Dean Cheng

1989-06-01T23:59:59.000Z

345

Microbase Cloud Products and Associated Heating Rates in the...  

NLE Websites -- All DOE Office Websites (Extended Search)

Microbase Cloud Products and Associated Heating Rates in the Tropical Western Pacific J. H. Mather and S. A. McFarlane Pacific Northwest National Laboratory Richland, Washington...

346

A TWP-ICE High-Level Cloud Case Study  

NLE Websites -- All DOE Office Websites (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...

347

Thin Liquid Water Clouds: Their Importance and Our Challenge  

Science Conference Proceedings (OSTI)

Many of the clouds important to the Earth's energy balance, from the Tropics to the Arctic, contain small amounts of liquid water. Longwave and shortwave radiative fluxes are very sensitive to small perturbations of the cloud liquid water path (...

D. D. Turner; A. M. Vogelmann; K. Johnson; M. Miller; R. T. Austin; J. C. Barnard; C. Flynn; C. Long; S. A. McFarlane; K. Cady-Pereira; S. A. Clough; J. C. Chiu; M. M. Khaiyer; J. Liljegren; B. Lin; P. Minnis; A. Marshak; S. Y. Matrosov; Q. Min; W. O'Hirok; Z. Wang; W. Wiscombe

2007-02-01T23:59:59.000Z

348

Cloud Clusters and Superclusters over the Oceanic Warm Pool  

Science Conference Proceedings (OSTI)

Infrared satellite images of the oceanic warm-pool region (8O°E-160°W) have been objectively processed to reveal tropicalcloud clusters” with temperature colder than a given threshold. Cloud clusters span a somewhat lognormal distribution of ...

Brain E. Mapes; Robert A. Houze Jr.

1993-05-01T23:59:59.000Z

349

The Thermal Structure of Tropical Easterly Waves  

Science Conference Proceedings (OSTI)

A procedure is introduced to derive a general balance condition for synoptic-scale disturbances in the tropics. The condition describes a balance between the mean pressure and momentum fields, and the pressure forcing by cumulus clouds. A simple ...

Han-Ruo Cho; Mary Ann Jenkins

1987-09-01T23:59:59.000Z

350

A Tropical "NAT-like" belt observed from space  

E-Print Network (OSTI)

The optical properties of cold tropical tropopause clouds are examined on a global scale, using two years of space-borne lidar observations from CALIPSO (June 2006 ? May 2008). The linear depolarization ratio, color ratio and backscatter signal are analyzed in tropical clouds colder than 200 K in a way similar to recent studies of Polar Stratospheric Clouds (PSCs). It is found that the three categories of particles encountered in PSC (Ice, Sulfate Ternary Solutions or STS, and Nitric Acid Trihydrate or NAT) do also occur in tropical cold cloud layers. Particles with optical properties similar to NAT are few, but they cover the tropical belt and represent about 20% of cold cloud tropical particles. The optical behavior of these particles requires them to be small, non-spherical, optically thin, and persistent in the TTL at temperatures colder than 200 K; NAT particles and very small ice crystals meet these criteria.

Chepfer, Hélène; 10.1029/2008GL036289

2009-01-01T23:59:59.000Z

351

Scale Dependence of Solar Heating Rates in Convective Cloud Systems with Implications to General Circulation Models  

Science Conference Proceedings (OSTI)

The authors examine 3D solar radiative heating rates within tropical convective–cirrus systems to identify the scales that contribute significantly to the spatial average over a climate model’s grid cell (i.e., its grid mean), and determine their ...

A. M. Vogelmann; V. Ramanathan; I. A. Podgorny

2001-04-01T23:59:59.000Z

352

ARM - Publications: Science Team Meeting Documents: Nighttime cirrus  

NLE Websites -- All DOE Office Websites (Extended Search)

Nighttime cirrus detection using AIRS radiances and total column Nighttime cirrus detection using AIRS radiances and total column precipitable water Kahn, Brian Jet Propulsion Laboratory Liou, Kuo-Nan UCLA A method of cirrus detection at nighttime is presented that utilizes 3.8 and 10.4 m infrared (IR) window brightness temperature differences (dBT) and total column precipitable water (PW) measurements. This technique is applied to the Atmospheric Infrared Sounder (AIRS) and Advanced Microwave Sounding Unit A (AMSU-A) instrument suite onboard EOS-Aqua, where dBT is determined from sets of carefully selected AIRS window channels, while PW is derived from the synergistic AIRS and AMSU-A water vapor retrievals. Simulated and observed dBT for a particular value of PW is not constant; several physical factors impact dBT, including the variability in

353

Long-Term Behavior of Cloud Systems in TOGA COARE and Their Interactions with Radiative and Surface Processes. Part I: Two-Dimensional Modeling Study  

Science Conference Proceedings (OSTI)

Two-dimensional cloud-resolving modeling of tropical cloud systems was performed for a 39-day period (5 December 1992 through 12 January 1993) during the Tropical Ocean Global Atmosphere (TOGA) Coupled Ocean–Atmosphere Response Experiment (COARE)...

Xiaoqing Wu; Wojciech W. Grabowski; Mitchell W. Moncrieff

1998-09-01T23:59:59.000Z

354

A Diagnostic Study of the Intensity of Three Tropical Cyclones in the Australian Region. Part I: A Synopsis of Observed Features of Tropical Cyclone Kathy (1984)  

Science Conference Proceedings (OSTI)

Objective streamline analyses and digitized high-resolution IR satellite cloud data have been used to examine in detail the changes in the environmental circulation and in the cloud structure that took place in and around Tropical Cyclone Kathy (...

France Lajoie; Kevin Walsh

2010-01-01T23:59:59.000Z

355

Cloud Geometry Effects on Atmospheric Solar Absorption  

Science Conference Proceedings (OSTI)

A 3D broadband solar radiative transfer scheme is formulated by integrating a Monte Carlo photon transport algorithm with the Fu–Liou radiation model. It is applied to fields of tropical mesoscale convective clouds and subtropical marine boundary ...

Qiang Fu; M. C. Cribb; H. W. Barker; S. K. Krueger; A. Grossman

2000-04-01T23:59:59.000Z

356

The Effects of Vertical Wind Shear on the Distribution of Convection in Tropical Cyclones  

Science Conference Proceedings (OSTI)

The influence of vertical wind shear on the azimuthal distribution of cloud-to-ground lightning in tropical cyclones was examined using flash locations from the National Lightning Detection Network. The study covers 35 Atlantic basin tropical ...

Kristen L. Corbosiero; John Molinari

2002-08-01T23:59:59.000Z

357

Formation and Quasi-Periodic Behavior of Outer Spiral Rainbands in a Numerically Simulated Tropical Cyclone  

Science Conference Proceedings (OSTI)

The formation and quasi-periodic behavior of outer spiral rainbands in a tropical cyclone simulated in the cloud-resolving tropical cyclone model version 4 (TCM4) are analyzed. The outer spiral rainbands in the simulation are preferably initiated ...

Qingqing Li; Yuqing Wang

2012-03-01T23:59:59.000Z

358

The Role of Longwave Radiation and Boundary Layer Thermodynamics in Forcing Tropical Surface Winds  

Science Conference Proceedings (OSTI)

This paper reveals major deficiencies of the existing intermediate climate models for tropical surface winds and elaborates the important roles of cloud-longwave radiational forcing and boundary layer thermodynamics in driving the tropical ...

Xiouhua Fu; Bin Wang

1999-04-01T23:59:59.000Z

359

Examination of New CERES Data for Evidence of Tropical Iris Feedback  

Science Conference Proceedings (OSTI)

New data products from the Clouds and the Earth's Radiant Energy System (CERES) instrument on the Tropical Rainfall Measuring Mission Satellite have been examined in the context of the recently proposed adaptive tropical infrared Iris hypothesis. ...

Lin H. Chambers; Bing Lin; David F. Young

2002-12-01T23:59:59.000Z

360

How Do Outer Spiral Rainbands Affect Tropical Cyclone Structure and Intensity?  

Science Conference Proceedings (OSTI)

A long-standing issue on how outer spiral rainbands affect the structure and intensity of tropical cyclones is studied through a series of numerical experiments using the cloud-resolving tropical cyclone model TCM4. Because diabatic heating due ...

Yuqing Wang

2009-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

A Modeling Study on the Early Electrical Development of Tropical Convection: Continental and Oceanic (Monsoon) Storms  

Science Conference Proceedings (OSTI)

Numerical modeling studies of continental tropical and maritime tropical convection were conducted using the two-dimensional, nonhydrostatic, cloud electrification model developed at the South Dakota School of Mines and Technology. The model ...

Scot C. Randell; Steven A. Rutledge; Richard D. Farley; John H. Helsdon Jr.

1994-08-01T23:59:59.000Z

362

Assessing the Radiative Impact of Clouds of Low Optical Depth  

NLE Websites -- All DOE Office Websites (Extended Search)

the Radiative Impact of Clouds of the Radiative Impact of Clouds of Low Optical Depth W. O'Hirok and P. Ricchiazzi Institute for Computational Earth System Science University of California Santa Barbara, California C. Gautier Department of Geography and Institute for Computational Earth System Science University of California Santa Barbara, California Introduction Analysis from the International Satellite Cloud Climatology Project (ISCCP) reveals that the global mean cloud optical depth is surprisingly low (i.e., Ï„ = 3.8). While this value is probably dominated by extensive fields of cirrus, the average for liquid water clouds is also likely smaller than expected. It is in this regime (Ï„ <10) where remote measurements of cloud optical thickness or liquid water path (LWP)

363

1  

NLE Websites -- All DOE Office Websites (Extended Search)

Cirrus Radiative Properties in the Tropical Western Pacific Cirrus Radiative Properties in the Tropical Western Pacific J. M. Comstock and T. P. Ackerman Pacific Northwest National Laboratory Richland, Washington G. G. Mace University of Utah Salt Lake City, Utah Introduction Cirrus clouds in tropical regions are often located high in the cold upper troposphere and have low optical depths. In addition, tropical cirrus often extend in large sheets up to 1000 km horizontally, which may have a large influence on the energy budget of the atmosphere. Characterizing the location and radiative properties of cirrus clouds is an important step in understanding the processes that generate and maintain these cold, thin cirrus clouds and their impact on upper tropospheric dynamics. In this paper, we present cirrus radiative properties derived using a combination of Micropulse Lidar

364

IC cloud: Enabling compositional cloud  

Science Conference Proceedings (OSTI)

Cloud computing has attracted great interest from both academic and industrial communities. Different paradigms, architectures and applications based on the concept of cloud have emerged. Although many of them have been quite successful, efforts are ... Keywords: Cloud computing, cloud elasticity, cloud service, compositional cloud, infrastructure as a service (IaaS)

Yi-Ke Guo; Li Guo

2011-08-01T23:59:59.000Z

365

Effective Radius of Ice Particles in Cirrus and Contrails  

Science Conference Proceedings (OSTI)

This paper discusses the ratio C between the volume mean radius and the effective radius of ice particles in cirrus and contrails. The volume mean radius is proportional to the third root of the ratio between ice water content and number of ice ...

U. Schumann; B. Mayer; K. Gierens; S. Unterstrasser; P. Jessberger; A. Petzold; C. Voigt; J-F. Gayet

2011-02-01T23:59:59.000Z

366

Properties of tropical convection observed by ARM millimeter-radars  

NLE Websites -- All DOE Office Websites (Extended Search)

Properties of tropical convection observed by ARM millimeter-radars 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 cloud classes according to the radar reflectivity structures of these cloud systems, associated rainfall, and surface radiative properties. These observations of cloud properties are composited with respect to various phases of the Madden Julian Oscillation, which is a dominant mode of variability at Manus Island. A method of better

367

The Effect of Environmental Conditions on Tropical Deep Convective Systems Observed from the TRMM Satellite  

Science Conference Proceedings (OSTI)

This study uses measurements of radiation and cloud properties taken between January and August 1998 by three Tropical Rainfall Measuring Mission (TRMM) instruments, the Clouds and the Earth’s Radiant Energy System (CERES) scanner, the TRMM ...

Bing Lin; Bruce A. Wielicki; Patrick Minnis; Lin Chambers; Kuan-Man Xu; Yongxiang Hu; Alice Fan

2006-11-01T23:59:59.000Z

368

Variability of Graupel and Snow Observed in Tropical Oceanic Convection by Aircraft during TRMM KWAJEX  

Science Conference Proceedings (OSTI)

Empirical characterization of graupel and snow in precipitating tropical convective clouds is important for refining satellite precipitation retrieval algorithms and cloud-resolving and radiative transfer models. Microphysics data for this ...

Ellen M. Sukovich; David E. Kingsmill; Sandra E. Yuter

2009-02-01T23:59:59.000Z

369

Final Technical Report on Scaling Models of the Internal Variability of Clouds DoE Grant No. DE-FG02-04ER63773  

SciTech Connect

The purpose of this proposal is to gain a better understanding of the space-time correlations of atmospheric fluctuations in clouds through application of methods from statistical physics to high resolution, continuous data sets of cloud observations available at the Department of Energy Atmospheric Radiation Measurement Program archive. In this report we present the accomplishments achieved during the four year period. Starting with the most recent one, we report on two break-throughs in our research that make the fourth year of the project exceptionally successful and markedly outperforming the objectives. The first break-through is on characterization of the structure of cirrus radiative properties at large, intermediate and small, generating cells scales by applying the Fokker-Planck equation method and other methods to ARM millimeter wavelength radar observations collected at the Southern Great Plains site. The second break-through is that we show that different characterizations of the cirrus radiative properties are obtained for different synoptic scale environments. We outline a stochastic approach to investigate the internal structure of radiative properties of cirrus clouds based on empirical modeling and draw conclusions about cirrus dynamical properties in the context of the synoptic environment. Results on the structure of cirrus dynamical properties are consistent with the structure of cirrus based on aircraft in situ measurements, with results from ground-based Raman lidar, and with results from model studies. These achievements would not have been possible without the accomplishments from the previous years on a number of problems that involve application of methods of analysis such as the Fokker-Planck equation approach, Tsallis nonextensive statistical mechanics, detrended fluctuation analysis, and others. These include stochastic analysis of neutrally stratified cirrus layers, internal variability and turbulence in cirrus, dynamical model and nonextensive statistical mechanics of liquid water path fluctuations, etc.

Ivanova, Kristinka

2008-04-24T23:59:59.000Z

370

Cloud-to-Ground Lightning Observations from TOGA COARE: Selected Results and Lightning Location Algorithms  

Science Conference Proceedings (OSTI)

Recently, observations of electrified oceanic convection and associated cloud-to-ground (CG) lightning were obtained over the tropical western Pacific Ocean during TOGA COARE (Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response ...

Walter A. Petersen; Steven A. Rutledge; Richard E. Orville

1996-04-01T23:59:59.000Z

371

Response of Cumulus Clouds to Large-Scale Forcing Using the Arakawa-Schubert Cumulus Parameterization  

Science Conference Proceedings (OSTI)

A cumulus parameterization scheme developed by Arakawa and Schubert was tested through a semiprognostic approach using two different datasets: one for a tropical cloud band, the other for tropical composite easterly wave disturbances. Both were ...

Chih-Yue Jim Kao; Yoshi Ogura

1987-09-01T23:59:59.000Z

372

Possibility of the Visible-Channel Calibration Using Deep Convective Clouds Overshooting the TTL  

Science Conference Proceedings (OSTI)

The authors examined the possible use of deep convective clouds (DCCs), defined as clouds that overshoot the tropical tropopause layer (TTL), for the calibration of satellite measurements at solar channels. DCCs are identified in terms of the ...

B-J. Sohn; Seung-Hee Ham; Ping Yang

2009-11-01T23:59:59.000Z

373

TWP Island Cloud Trail Studies  

NLE Websites -- All DOE Office Websites (Extended Search)

Pacific Island Cloud Trail Studies Pacific Island Cloud Trail Studies W. M. Porch Los Alamos National Laboratory Los Alamos, New Mexico S. Winiecki University of Chicago Chicago, Illinois Introduction Images and surface temperature measurements from the U.S. Department of Energy (DOE) Multi- spectral Thermal Imaging (MTI) satellite are combined with geostationary meteorological satellite (GMS) images during 2000 and 2001 to better understand cloud trail formation characteristics from the Atmospheric Radiation Measurement (ARM) Tropical Western Pacific (TWP) site. Figure 1 shows a comparison on two consecutive days in December 2000. The day for which a cloud trail developed was more moist and cooler at the altitude the cloud developed (about 600 m) and there was very little

374

Thin Cloud Length Scales Using CALIPSO and CloudSat Data  

E-Print Network (OSTI)

Thin clouds are the most difficult cloud type to observe. The recent availability of joint cloud products from the active remote sensing instruments aboard CloudSat and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite (CALIPSO) facilitates the study of these clouds. Using one of these joint cloud products, 2B-GEOPROF-Lidar, and a post-processing algorithm designed to find horizontally continuous thin clouds within the cloud product, the locations, length scales, and vertical distributions by length of thin clouds are determined. It is found that thin clouds vary in length from a few km to over 2900 km and tend to be longer in the tropical upper troposphere than lower in the atmosphere and at higher latitudes. In the upper troposphere between 0° and 40°N, over 20% of all thin cloud measurements in the 2B-GEOPROF-Lidar product are contributed by thin clouds that are longer than 500 km. In fact, in this latitude range, over 65% of all thin cloud measurements are contributed by clouds longer than 100 km. Also, thin cloud length and frequency differ between the four seasons in the year of data used here.

Solbrig, Jeremy E.

2009-08-01T23:59:59.000Z

375

Relationship between Ice Water Path and Downward Longwave Radiation for Clouds Optically Thin in the Infrared: Observations and Model Calculations  

Science Conference Proceedings (OSTI)

A vertically pointing 3.2-cm radar is used to observe altostratus and cirrus clouds as they pass overhead. Radar reflectivities are used in combination with an empirical Zi-IWC (ice water content) relationship developed by Sassen (1987) to ...

Taneil Uttal; Sergey Y. Matrosov; Jack B. Snider; Robert A. Kropfli

1994-03-01T23:59:59.000Z

376

Modeling Study of a Tropical Squall-Type Convective Line  

Science Conference Proceedings (OSTI)

A multidimensional and time-dependent cloud scale model is used to investigate the dynamic and micro-physical processes associated with convective and stratiform regions within a tropical squall-type convective line. The evolution of the total ...

Wei-Kuo Tao; Joanne Simpson

1989-01-01T23:59:59.000Z

377

Thermodynamic Environments of Deep Convection in Atlantic Tropical Disturbances  

Science Conference Proceedings (OSTI)

Conditional composites of dropsondes deployed into eight tropical Atlantic weather systems during 2010 are analyzed. The samples are conditioned based on cloud-top temperature within 10 km of the dropsonde, the radius from the cyclonic circulation ...

Christopher A. Davis; David A. Ahijevych

2013-07-01T23:59:59.000Z

378

Lightning Distribution and Eyewall Outbreaks in Tropical Cyclones during Landfall  

Science Conference Proceedings (OSTI)

Cloud-to-ground lightning data and storm intensity data (winds and central pressure) for 33 northwest Pacific tropical cyclones were used to analyze lightning distributions during the period of landfall in China. Lightning activities varied ...

Wenjuan Zhang; Yijun Zhang; Dong Zheng; Xiuji Zhou

2012-11-01T23:59:59.000Z

379

Transient Environmental Sensitivities of Explicitly Simulated Tropical Convection  

Science Conference Proceedings (OSTI)

A three-dimensional cloud-resolving model, maintained in a statistically steady convecting state by tropics-like forcing, is subjected to sudden (10 min) stimuli consisting of horizontally homogeneous temperature and/or moisture sources with ...

Stefan N. Tulich; Brian E. Mapes

2010-04-01T23:59:59.000Z

380

On the Annual Cycle in the Tropical Eastern Central Pacific  

Science Conference Proceedings (OSTI)

In the tropical eastern central Pacific Ocean, the annual cycle in sea surface temperature (SST), surface winds and pressure, and clouds are alternatively dominated by an antisymmetric (with respect to the equator) monsoonal mode in February and ...

Bin Wang

1994-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Influence of Environmental Humidity on Tropical Cyclone Size  

Science Conference Proceedings (OSTI)

Observations demonstrate that the radius of maximum winds in tropical cyclones (TCs) can vary by an order of magnitude; similar size differences are evident in other spatial measures of the wind field as well as in cloud and precipitation fields. ...

Kevin A. Hill; Gary M. Lackmann

2009-10-01T23:59:59.000Z

382

A Vortical Hot Tower Route to Tropical Cyclogenesis  

Science Conference Proceedings (OSTI)

A nonhydrostatic cloud model is used to examine the thermomechanics of tropical cyclogenesis under realistic meteorological conditions. Observations motivate the focus on the problem of how a midtropospheric cyclonic vortex, a frequent by-product ...

M. T. Montgomery; M. E. Nicholls; T. A. Cram; A. B. Saunders

2006-01-01T23:59:59.000Z

383

Angular Distribution Models for Top-of-Atmosphere Radiative Flux Estimation from the Clouds and the Earth’s Radiant Energy System Instrument on the Tropical Rainfall Measuring Mission Satellite. Part I: Methodology  

Science Conference Proceedings (OSTI)

Clouds and the Earth's Radiant Energy System (CERES) investigates the critical role that clouds and aerosols play in modulating the radiative energy flow within the Earth–atmosphere system. CERES builds upon the foundation laid by previous ...

Norman G. Loeb; Natividad Manalo-Smith; Seiji Kato; Walter F. Miller; Shashi K. Gupta; Patrick Minnis; Bruce A. Wielicki

2003-02-01T23:59:59.000Z

384

Two-moment Bulk Stratiform Cloud Microphysics in the Grid-point Atmospheric Model of IAP LASG (GAMIL)  

SciTech Connect

A two-moment bulk stratiform microphysics scheme, including recently developed physically-based droplet activation/ice nucleation parameterizations has been implemented into the Grid-point Atmospheric Model of IAP LASG (GAMIL) as an effort to enhance the model capability for studying aerosol indirect effects. Unlike the previous one-moment cloud microphysics scheme, the new scheme produces reasonable representation of cloud particle size and number concentration. This scheme captures the observed spatial variations in cloud droplet number concentrations. Simulated ice crystal number concentrations in cirrus clouds qualitatively agree with in-situ observations. The longwave and shortwave cloud forcing are in better agreement with observations. Sensitivity tests show that the column cloud droplet number concentrations calculated from two different droplet activation parameterizations are similar. However, ice crystal number concentration in mixed-phased clouds is sensitive to different heterogeneous freezing formulations. The simulation with high ice crystal number concentration in mixed-phase clouds has less liquid water path and weaker cloud forcing. Furthermore, ice crystal number concentration in cirrus clouds is sensitive to different ice nucleation parameterizations. Sensitivity tests also suggest that impact of pre-existing ice crystals on homogeneous freezing in old clouds should be taken into account.

Shi, Xiangjun; Wang, Bin; Liu, Xiaohong; Wang, Minghuai

2013-05-01T23:59:59.000Z

385

A Technique to Determine the Radius of Maximum Wind of a Tropical Cyclone  

Science Conference Proceedings (OSTI)

A simple technique is developed that enables the radius of maximum wind of a tropical cyclone to be estimated from satellite cloud data. It is based on the characteristic cloud and wind structure of the eyewall of a tropical cyclone, after the ...

France Lajoie; Kevin Walsh

2008-10-01T23:59:59.000Z

386

Rainfall Observation from Tropical Rainfall Measuring Mission (TRMM) Satellite  

Science Conference Proceedings (OSTI)

National Space Development Agency of Japan (NASDA) successfully launched the Tropical Rainfall Measuring Mission (TRMM) observatory at 06:27 (JST) on Nov. 28, 1997. The TRMM satellite carries the first spaceborne Precipitation Radar (PR) which was developed ... Keywords: Clouds and the Earth's Radiant Energy System (CERES), El Niño, Lightning Imaging Sensor (LIS), Precipitation Radar (PR), TRMM Microwave Imager (TMI), Tropical Rainfall Measuring Mission (TRMM), Visible Infrared Scanner (VIRS), heavy rain, tropical cyclone

K. Hiroshima

1999-01-01T23:59:59.000Z

387

Retrieval of Cloud Phase Using the Moderate Resolution Imaging Spectroradiometer Data during the Mixed-Phase Arctic Cloud Experiment  

SciTech Connect

Improving climate model predictions over Earth's polar regions requires a comprehensive knowledge of polar cloud microphysics. Over the Arctic, there is minimal contrast between the clouds and background snow surface, making it difficult to detect clouds and retrieve their phase from space. Snow and ice cover, temperature inversions, and the predominance of mixed-phase clouds make it even more difficult to determine cloud phase. Also, since determining cloud phase is the first step toward analyzing cloud optical depth, particle size, and water content, it is vital that the phase be correct in order to obtain accurate microphysical and bulk properties. Changes in these cloud properties will, in turn, affect the Arctic climate since clouds are expected to play a critical role in the sea ice albedo feedback. In this paper, the IR trispectral technique (IRTST) is used as a starting point for a WV and 11-{micro}m brightness temperature (T11) parameterization (WVT11P) of cloud phase using MODIS data. In addition to its ability to detect mixed-phase clouds, the WVT11P also has the capability to identify thin cirrus clouds overlying mixed or liquid phase clouds (multiphase ice). Results from the Atmospheric Radiation Measurement (ARM) MODIS phase model (AMPHM) are compared to the surface-based cloud phase retrievals over the ARM North Slope of Alaska (NSA) Barrow site and to in-situ data taken from University of North Dakota Citation (CIT) aircraft which flew during the Mixed-Phase Arctic Cloud Experiment (MPACE). It will be shown that the IRTST and WVT11P combined to form the AMPHM can achieve a relative high accuracy of phase discrimination compared to the surface-based retrievals. Since it only uses MODIS WV and IR channels, the AMPHM is robust in the sense that it can be applied to daytime, twilight, and nighttime scenes with no discontinuities in the output phase.

Spangenberg, D.; Minnis, P.; Shupe, M.; Uttal, T.; Poellot, M.

2005-03-18T23:59:59.000Z

388

SST Sensitivities in Multiday TOGA COARE Cloud-Resolving Simulations  

Science Conference Proceedings (OSTI)

A two-dimensional cloud-resolving model (CRM) was used to simulate the evolution of convection over the western Pacific between 19 and 26 December 1992, during the Tropical Ocean Global Atmosphere Coupled Ocean–Atmosphere Response Experiment. A ...

Alexandre A. Costa; William R. Cotton; Robert L. Walko; Roger A. Pielke Sr.; Hongli Jiang

2001-02-01T23:59:59.000Z

389

Satellite-Observed Characteristics of Winter Monsoon Cloud Clusters  

Science Conference Proceedings (OSTI)

An objective algorithm is devised which is capable of touting tropical cloud clusters at the point of initiation, tracking them to the paint of dissipation and thereby accumulating statistics on their size distributions and preferred geographical ...

Mark Williams; Robert A. Houze Jr.

1987-02-01T23:59:59.000Z

390

Stratocumulus Clouds  

Science Conference Proceedings (OSTI)

This paper reviews the current knowledge of the climatological, structural, and organizational aspects of stratocumulus clouds and the physical processes controlling them. More of Earth’s surface is covered by stratocumulus clouds than by any ...

Robert Wood

2012-08-01T23:59:59.000Z

391

Small-Scale Cloud Activity over the Maritime Continent and the Western Pacific as Revealed by Satellite Data  

Science Conference Proceedings (OSTI)

Cloud systems over the Maritime Continent and the tropical western Pacific defined by the Geostationary Meteorological Satellite (GMS) were tracked, and their evolution was compared with cloud parameters [e.g., minimum blackbody brightness ...

Yoshimi Kondo; Atsushi Higuchi; Kenji Nakamura

2006-06-01T23:59:59.000Z

392

The Influence of the 1998 El Niño upon Cloud-Radiative Forcing over the Pacific Warm Pool  

Science Conference Proceedings (OSTI)

Clouds cool the climate system by reflecting shortwave radiation and warm it by increasing the atmospheric greenhouse. Previous studies have shown that in tropical regions of deep convection there is a near cancellation between cloud-induced ...

Robert D. Cess; Minghua Zhang; Bruce A. Wielicki; David F. Young; Xue-Long Zhou; Yuri Nikitenko

2001-05-01T23:59:59.000Z

393

EPA/600/X-99/XXX December 1999  

E-Print Network (OSTI)

distribution of optically96 thin cirrus in the tropical tropopause transition layer (TTL) have also received and spatial structure of cirrus in the TTL has been linked to tropical stratospheric99 waves in field-Dobson circulation and103 cloud amount in both the TTL and Arctic troposphere [Li and Thompson, 2013

Pitt, Robert E.

394

A Parameterization of the Particle Size Spectrum of Ice Clouds in Terms of the Ambient Temperature and the Ice Water Content  

Science Conference Proceedings (OSTI)

A data set obtained in cirrus clouds has been examined to deduce any dependencies of the particle size spectral form or the crystal habit on the temperature. It was found that both form of the spectra and crystal habit changed systematically with ...

Andrew J. Heymsfield; C. M. R. Platt

1984-03-01T23:59:59.000Z

395

Leading and Trailing Anvil Clouds of West African Squall Lines  

Science Conference Proceedings (OSTI)

The anvil clouds of tropical squall-line systems over West Africa have been examined using cloud radar data and divided into those that appear ahead of the leading convective line and those on the trailing side of the system. The leading anvils ...

Jasmine Cetrone; Robert A. Houze Jr.

2011-05-01T23:59:59.000Z

396

The Optical Properties of Equatorial Cirrus from Observations in the ARM Pilot Radiation Observation Experiment  

Science Conference Proceedings (OSTI)

The optical properties of equatorial cirrus were studied during a three-week period of the ARM Pilot Radiation and Observation Experiment at Kavieng, Papua New Guinea, in January and February 1993. The experiment consisted of vertical lidar (532 ...

C. M. R. Platt; S. A. Young; P. J. Manson; G. R. Patterson; S. C. Marsden; R. T. Austin; J. H. Churnside

1998-06-01T23:59:59.000Z

397

Angular Distribution Models for Top-of-Atmosphere Radiative Flux Estimation from the Clouds and the Earth's Radiant Energy System Instrument on the Tropical Rainfall Measuring Mission Satellite. Part II: Validation  

Science Conference Proceedings (OSTI)

Top-of-atmosphere (TOA) radiative fluxes from the Clouds and the Earth's Radiant Energy System (CERES) are estimated from empirical angular distribution models (ADMs) that convert instantaneous radiance measurements to TOA fluxes. This paper ...

Norman G. Loeb; Konstantin Loukachine; Natividad Manalo-Smith; Bruce A. Wielicki; David F. Young

2003-12-01T23:59:59.000Z

398

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

SciTech Connect

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.

Reeder, Michael J. [Monash University; Lane, Todd P. [University of Melbourne; Hankinson, Mai Chi Nguyen [Monash University

2013-09-27T23:59:59.000Z

399

Cloud Chmabers  

NLE Websites -- All DOE Office Websites (Extended Search)

Video - (Requires Windows Media Player) Build your own cloud chamber - Instructions Project Contact: Tom Jordan Web Maintainer: qnet-webmaster@fnal.gov Last Update: May 31, 2011...

400

A tropical « NAT-like » belt observed from space  

E-Print Network (OSTI)

The optical properties of cold tropical tropopause clouds are examined on a global scale, using two years of space-borne lidar observations from CALIPSO (June 2006- May 2008). The linear depolarization ratio, color ratio and backscatter signal are analyzed in tropical clouds colder than 200 K in a way similar to recent studies of Polar Stratospheric Clouds (PSCs). It is found that the three categories of particles encountered in PSC (Ice, Sulfate Ternary Solutions or STS, and Nitric Acid Trihydrate or NAT) do also occur in tropical cold cloud layers. Particles with optical properties similar to NAT are few, but they cover the hal-00439695, version 1- 8 Dec 2009 tropical belt and represent about 20 % of cold cloud tropical particles all year long. The optical behavior of these particles requires them to be very small, non-spherical, optically thin, and persistent in the TTL at temperatures colder than 200 K; NAT particles and very small ice crystals meet these criteria and are right now the best candidates to explain the presented observations. 2

unknown authors

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Improving Retrievals of Cirrus Cloud Particle Size Coupling Lidar and Three-Channel Radiometric Techniques  

Science Conference Proceedings (OSTI)

This study is intended to illustrate the potential advantage of combining lidar measurements and the split-window technique based on the infrared spectral information contained at the 8.65-, 11.15-, and 12.05-?m bands for inferring the ...

M. Chiriaco; H. Chepfer; V. Noel; A. Delaval; M. Haeffelin; P. Dubuisson; P. Yang

2004-07-01T23:59:59.000Z

402

Radiative Transfer in Cirrus Clouds. Part III: Light Scattering by Irregular Ice Crystals  

Science Conference Proceedings (OSTI)

A new Monte Carlo/geometric ray-tracing method has been developed for the computation of the scattering, absorption, and polarization properties of ice crystals with various irregular structure, including hollow columns, bullet rosettes, ...

Y. Takano; K. N. Liou

1995-04-01T23:59:59.000Z

403

Remote sensing of cirrus cloud particle size and optical depth using polarimetric sensor measurements  

E-Print Network (OSTI)

M. Cai, 1991: Scattering phase matrices of ice crystals with44 For nonspherical ice crystals, the phase function, P 11 ,hexagonal ice crystals and compared phase-matrix elements

Ou, Szu-cheng C; Liou, K N; Takano, Y; Slonaker, R L

2005-01-01T23:59:59.000Z

404

Isentropic modeling of a cirrus cloud event observed in the midlatitude upper troposphere and lower stratosphere  

E-Print Network (OSTI)

´so-e´chelle de l'Ozone Stratosphe´rique par Advection (MIMOSA) model to take into account the three phases for fall speeds around 1 cm/s and gives ice water content around 3­4 mg/m3 . Fall speed is also a critical parameter, and a better parameterization with altitude or other atmospheric conditions in the modeling

Brogniez, Hélène

405

A General Approach for Deriving the Properties of Cirrus and Stratiform Ice Cloud Particles  

Science Conference Proceedings (OSTI)

A new approach is described for calculating the mass (m) and terminal velocity (Vt) of ice particles from airborne and balloon-borne imaging probe data as well as its applications for remote sensing and modeling studies. Unlike past studies that ...

Andrew J. Heymsfield; Sharon Lewis; Aaron Bansemer; Jean Iaquinta; Larry M. Miloshevich; Masahiro Kajikawa; Cynthia Twohy; Michael R. Poellot

2002-01-01T23:59:59.000Z

406

Stratospheric Ion and Aerosol Chemistry and Possible Links with Cirrus Cloud Microphysics—A Critical Assessment  

Science Conference Proceedings (OSTI)

It has been postulated that variations in galactic cosmic rays could affect production of stratospheric aerosols which, after transport to the upper troposphere, could affect latent heat release in convective and cyclonic systems. This hypothesis ...

Volker A. Mohnen

1990-08-01T23:59:59.000Z

407

Cellular clouds  

Science Conference Proceedings (OSTI)

This paper progresses an analysis of what it means to be a cellular network operator and what form the ownership and control of future cellular networks may take. Alternative modes of ownership may allow for the creation of more flexible cellular networking ... Keywords: Cellular Cloud, Cellular network, Cloud Computing, Cognitive radio, DSA, LTE, MVNO, Services, Utility Cellular Network

Tim Forde; Linda Doyle

2013-03-01T23:59:59.000Z

408

Parameterization of ice cloud radiative properties and its application to the potential climatic importance of mixed-phase clouds  

SciTech Connect

It is often assumed, in modeling and radiation budget simulation, that clouds below the cirrus level are entirely in the liquid phase. There is substantive evidence from observations that low and middle clouds are often of mixed phase. Using a light-scattering program for hexagonal crystals, the authors update a parameterization of the radiative properties of ice clouds from an earlier study and use the new parameterization to investigate the role of mixed-phase clouds in three areas: (i) the interpretation of ISCCP optical depth, (ii) the simulation of the earth radiation budget, and (iii) the sensitivity of a simple radiative-convective model to an increase in CO{sub 2}. In all cases, mixed-phase clouds are shown to have the potential to significantly modify the results obtained using liquid phase clouds. A precise quantification is not yet possible as the dependence of the fraction of ice and liquid water is mixed-phase clouds on atmospheric properties, and the way in which the ice and liquid water are mixed, are not known with sufficient detail. 43 refs., 17 figs., 2 tabs.

Sun, Z.; Shine, K.P. [Univ. of Reading (United Kingdom)] [Univ. of Reading (United Kingdom)

1995-07-01T23:59:59.000Z

409

Evaluating the MMF Using CloudSat  

NLE Websites -- All DOE Office Websites (Extended Search)

CloudSat, ARM, and the Multi CloudSat, ARM, and the Multi CloudSat, ARM, and the Multi - - scale scale Modeling Framework (MMF) in the Modeling Framework (MMF) in the Tropical Western Pacific Tropical Western Pacific Tom Ackerman Tom Ackerman University of Washington University of Washington Collaborators on the ARM Project Collaborators on the ARM Project Roger Marchand, U. Washington Roger Marchand, U. Washington Steve Klein, LLNL Steve Klein, LLNL Sally McFarlane, PNNL Sally McFarlane, PNNL Robert Pincus, U. Colorado (NY office) Robert Pincus, U. Colorado (NY office) Kuan Kuan - - Man Man Xu Xu , NASA Langley , NASA Langley Anning Anning Chen, Hampton University Chen, Hampton University Pete Henderson, U. Colorado Pete Henderson, U. Colorado Yunyan Zhang, LLNL Yunyan Zhang, LLNL

410

Hole-boring through clouds for laser power beaming  

Science Conference Proceedings (OSTI)

Power beaming to satellites with a ground-based laser can be limited by clouds. Hole-boring through the clouds with a laser has been proposed as a way to overcome this obstacle. This paper reviews the past work on laser hole-boring and concludes that hole-boring for direct beaming to satellites is likely to require 10--100 MW. However, it may be possible to use an airborne relay mirror at 10--25 km altitude for some applications in order to extend the range of the laser (e.g., for beaming to satellites near the horizon). In these cases, use of the relay mirror also would allow a narrow beam between the laser and the relay, as well as the possibility of reducing the crosswind if the plane matched speed with the cloud temporarily. Under these conditions, the power requirement to bore a hole through most cirrus and cirrostratus clouds might be only 500-kW if the hole is less than 1 m in diameter and if the crosswind speed is less than 10 m/s. Overcoming cirrus and cirrostratus clouds would reduce the downtime due to weather by a factor of 2. However, 500 kW is a large laser, and it may be more effective instead to establish a second power beaming site in a separate weather zone. An assessment of optimum wavelengths for hole boring also was made, and the best options were found to be 3.0--3.4 {mu}m and above 10 {mu}m.

Lipinski, R.J. [Sandia National Labs., Albuquerque, NM (United States); Walter, R.F. [W.J. Schafer Associates, Inc., Albuquerque, NM (United States)

1994-12-31T23:59:59.000Z

411

Multichannel Microwave Radiometric Observations at Saipan during the 1990 Tropical Cyclone Motion Experiment  

Science Conference Proceedings (OSTI)

To estimate mesoscale variations in integrated water vapor, cloud liquid water, and temperature in a tropical region, multiwavelength microwave radiometric observations were carried out over a seven-week period on the island of Saipan during the ...

Yong Han; Dennis W. Thomson

1994-02-01T23:59:59.000Z

412

Structural Characteristics of Deep Convective Systems over Tropical Africa and the Atlantic Ocean  

Science Conference Proceedings (OSTI)

The structural properties of convective cloud clusters of tropical Africa and the Atlantic Ocean are studied using six summers of Meteosat satellite data in the atmospheric infrared window. A cluster at a given brightness temperature threshold is ...

L. A. Toledo Machado; M. Desbois; J-Ph Duvel

1992-03-01T23:59:59.000Z

413

Observational Analyses of North Atlantic Tropical Cyclones from NOAA Polar-Orbiting Satellite Microwave Data  

Science Conference Proceedings (OSTI)

Passive microwave observations from the current NOAA series of polar-orbiting satellites of a large sample of North Atlantic tropical cyclones are qualitatively and quantitatively analyzed. Microwave observations can penetrate the cloud cover ...

Christopher S. Velden

1989-01-01T23:59:59.000Z

414

From Hot Towers to TRMM: Joanne Simpson and Advances in Tropical Convection Research  

Science Conference Proceedings (OSTI)

Joanne Simpson began contributing to advances in tropical convection about half a century ago. The hot tower hypothesis jointly put forth by Joanne Simpson and Herbert Riehl postulated that deep convective clouds populating the “equatorial trough ...

Robert A. Houze Jr.

2003-01-01T23:59:59.000Z

415

Inertial Available Kinetic Energy and the Dynamics of Tropical Plume Formation  

Science Conference Proceedings (OSTI)

Tropical plumes are identified in satellite data as elongated cloud bands originating from convective activity along the intertropical convergence zone (ITCZ), often extending far into the subtropics and middle latitudes. Many previous studies ...

John R. Mecikalski; Gregory J. Tripoli

1998-08-01T23:59:59.000Z

416

Observations of Lightning in Convective Supercells within Tropical Storms and Hurricanes  

Science Conference Proceedings (OSTI)

Cloud-to-ground (CG) lightning observations from land-based lightning detection networks now allow monitoring this component of the electrical structure of tropical storms and hurricanes within a few hundred kilometers of the United States ...

Walter A. Lyons; Cecil S. Keen

1994-08-01T23:59:59.000Z

417

The Interaction Between Deep Convection and Easterly Waves over Tropical North Africa: A Weather State Perspective  

Science Conference Proceedings (OSTI)

The interaction between deep convection and easterly waves over tropical North Africa is studied using a weather state (WS) dataset from the International Cloud Climatology Project (ISCCP) and reanalysis products from the European Centre for ...

Ademe Mekonnen; William B. Rossow

2011-08-01T23:59:59.000Z

418

Satellite Analysis of Tropical Cyclones Using the Advanced Microwave Sounding Unit (AMSU)  

Science Conference Proceedings (OSTI)

The first Advanced Microwave Sounding Unit (AMSU) was launched aboard the NOAA—15 satellite on 13 May 1998. The AMSU is well suited for the observation of tropical cyclones because its measurements are not significantly affected by the ice clouds ...

Stanley Q. Kidder; Mitchell D. Goldberg; Raymond M. Zehr; Mark DeMaria; James F. W. Purdom; Christopher S. Velden; Norman C. Grody; Sheldon J. Kusselson

2000-06-01T23:59:59.000Z

419

Using the Stochastic Multicloud Model to Improve Tropical Convective Parameterization: A Paradigm Example  

Science Conference Proceedings (OSTI)

Despite recent advances in supercomputing, current general circulation models (GCMs) poorly represent the variability associated with organized tropical convection. A stochastic multicloud convective parameterization based on three cloud types (...

Yevgeniy Frenkel; Andrew J. Majda; Boualem Khouider

2012-03-01T23:59:59.000Z

420

The Tropical Water and Energy Cycles in a Cumulus Ensemble Model. Part I: Equilibrium Climate  

Science Conference Proceedings (OSTI)

A cumulus ensemble model is used to study the tropical water and energy cycles and their role in the climate system. The model includes cloud dynamics, radiative processes, and microphysics that incorporate all important production and conversion ...

C. H. Sui; K. M. Lau; W. K. Tao; J. Simpson

1994-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

The Role of “Vortical” Hot Towers in the Formation of Tropical Cyclone Diana (1984)  

Science Conference Proceedings (OSTI)

A high-resolution (3-km horizontal grid spacing) near-cloud-resolving numerical simulation of the formation of Hurricane Diana (1984) is used to examine the contribution of deep convective processes to tropical cyclone formation. This study is ...

Eric A. Hendricks; Michael T. Montgomery; Christopher A. Davis

2004-06-01T23:59:59.000Z

422

Atmospheric Latent Heating Distributions in the Tropics Derived from Satellite Passive Microwave Radiometer Measurements  

Science Conference Proceedings (OSTI)

A method for the remote sensing of three-dimensional latent heating distributions in precipitating tropical weather systems from satellite passive microwave observations is presented. In this method, cloud model simulated hydrometeor/latent ...

William S. Olson; Christian D. Kummerow; Ye Hong; Wei-Kuo Tao

1999-06-01T23:59:59.000Z

423

Response of Tropical Deep Convection to Localized Heating Perturbations: Implications for Aerosol-Induced Convective Invigoration  

Science Conference Proceedings (OSTI)

A cloud-system-resolving model is used to investigate the effects of localized heating/cooling perturbations on tropical deep convection, in the context of the aerosol “invigoration effect.” This effect supposes that a reduction of droplet ...

Hugh Morrison; Wojciech W. Grabowski

2013-11-01T23:59:59.000Z

424

Postlaunch Radiometric Validation of the Clouds and the Earth’s Radiant Energy System (CERES) Proto-Flight Model on the Tropical Rainfall Measuring Mission (TRMM) Spacecraft through 1999  

Science Conference Proceedings (OSTI)

Each Clouds and the Earth’s Radiant Energy System (CERES) instrument contains three scanning thermistor bolometer radiometric channels. These channels measure broadband radiances in the shortwave (0.3–5.0 ?m), total (0.3–>100 ?m), and water vapor ...

Kory J. Priestley; Bruce R. Barkstrom; Robert B. Lee III; Richard N. Green; Susan Thomas; Robert S. Wilson; Peter L. Spence; Jack Paden; D. K. Pandey; Aiman Al-Hajjah

2000-12-01T23:59:59.000Z

425

ARM - 2008 ARM Science Team Meeting  

NLE Websites -- All DOE Office Websites (Extended Search)

and Tropical Cirrus 9:00 am - 9:20 am Xiaohong Liu: Evaluation of a New Mixed-phase Cloud Microphysics Parameterization with Single Column Model, CAPT Forecasts, and...

426

1  

NLE Websites -- All DOE Office Websites (Extended Search)

Cirrus Maintenance Cirrus Maintenance M. T. Boehm and J. Verlinde The Pennsylvania State University University Park, Pennsylvania Introduction Data from the Atmospheric Radiation Measurement (ARM) Program sites on Manus Island and Nauru in the tropical western Pacific reveal the frequent occurrence of high cirrus layers with lifetimes of several hours to several days. We are investigating the processes responsible for the development and maintenance of these clouds using observations and a cirrus cloud model. In a recent article we described results of a series of model runs designed to test the hypothesis that cloud circulations associated with radiative destabilization of the layer are responsible for the maintenance of high tropical cirrus (Boehm et al. 1999). In spite of significant differences in cloud circulation strength among the

427

Cloud computing beyond objects: seeding the cloud  

Science Conference Proceedings (OSTI)

Cloud computing is an emerging computing milieu which dynamically enables scalable and virtually unlimited resources. This panel will discuss emerging tools, skills and technologies that will ""seed the cloud"" - enabling improved interoperability, security, ... Keywords: cloud computing, skills, technologies, tools

Steven Fraser; Robert Biddle; Scott Jordan; Kate Keahey; Bob Marcus; E. Michael Maximilien; Dave Thomas

2009-10-01T23:59:59.000Z

428

A Combined Multisensor Optimal Estimation Retrieval Algorithm for Oceanic Warm Rain Clouds  

Science Conference Proceedings (OSTI)

The complicated interactions between cloud processes in the tropical hydrologic cycle and their responses to changes in environmental variables have been the focus of many recent investigations. Most studies that examine the response of the ...

Anita D. Rapp; G. Elsaesser; C. Kummerow

2009-11-01T23:59:59.000Z

429

Temporal Interpolation Methods for the Clouds and the Earth’s Radiant Energy System (CERES) Experiment  

Science Conference Proceedings (OSTI)

The Clouds and the Earth’s Radiant Energy System (CERES) is a NASA multisatellite measurement program for monitoring the radiation environment of the earth–atmosphere system. The CERES instrument was flown on the Tropical Rainfall Measuring ...

D. F. Young; P. Minnis; D. R. Doelling; G. G. Gibson; T. Wong

1998-06-01T23:59:59.000Z

430

Clouds and Shortwave Fluxes at Nauru. Part II: Shortwave Flux Closure  

Science Conference Proceedings (OSTI)

The datasets currently being collected by the Atmospheric Radiation Measurement (ARM) program on the islands of Nauru and Manus represent the longest time series of ground-based cloud measurements in the tropical western Pacific region. In this ...

Sally A. McFarlane; K. Franklin Evans

2004-11-01T23:59:59.000Z

431

A Comparison of the Water Budgets between Clouds from AMMA and TWP-ICE  

Science Conference Proceedings (OSTI)

Two field campaigns, the African Monsoon Multidisciplinary Analysis (AMMA) and the Tropical Warm Pool–International Cloud Experiment (TWP-ICE), took place in 2006 near Niamey, Niger, and Darwin, Northern Territory, Australia, providing extensive ...

Xiping Zeng; Wei-Kuo Tao; Scott W. Powell; Robert A. Houze Jr.; Paul Ciesielski; Nick Guy; Harold Pierce; Toshihisa Matsui

2013-02-01T23:59:59.000Z

432

Convective Forcing Fluctuations in a Cloud-Resolving Model: Relevance to the Stochastic Parameterization Problem  

Science Conference Proceedings (OSTI)

Idealized cloud-resolving model (CRM) simulations spanning a large part of the tropical atmosphere are used to evaluate the extent to which deterministic convective parameterizations fail to capture the statistical fluctuations in deep-convective ...

G. J. Shutts; T. N. Palmer

2007-01-01T23:59:59.000Z

433

Cloud, Surface Temperature, and Outgoing Longwave Radiation for the Period from 1979 to 1990  

Science Conference Proceedings (OSTI)

Quasi-biennial global, midlatitude, and tropical oscillations were observed using top-of-the-atmosphere outgoing longwave radiation (OLR), surface air temperature (SAT), and cloud amount for the period from 1979 to 1989. The in-phase quasi-...

H. Lee Kyle; Mitchell Weiss; Philip Ardanuy

1995-11-01T23:59:59.000Z

434

Characteristics of Precipitation, Cloud, and Latent Heating Associated with the Madden–Julian Oscillation  

Science Conference Proceedings (OSTI)

This study investigates the evolution of cloud and rainfall structures associated with Madden–Julian oscillation (MJO) using Tropical Rainfall Measuring Mission (TRMM) data. Two complementary indices are used to define MJO phases. Joint ...

K-M. Lau; H-T. Wu

2010-02-01T23:59:59.000Z

435

Atlantic Tropical Systems of 1988  

Science Conference Proceedings (OSTI)

.The 1988 season produced 62 tropical waves, 19 tropical depressions and 12 tropical storms, 5 of which became hurricanes. Eighty-three percent of the tropical storms developed from African waves. A comparison with the past 21 years is included.

Lixion A. Avila; Gilbert B. Clark

1989-10-01T23:59:59.000Z

436

GFDL ARM Project Technical Report: Using ARM Observations to Evaluate Cloud and Convection Parameterizations & Cloud-Convection-Radiation Interactions in the GFDL Atmospheric General Circulation Model  

SciTech Connect

This report briefly summarizes the progress made by ARM postdoctoral fellow, Yanluan Lin, at GFDL during the period from October 2008 to present. Several ARM datasets have been used for GFDL model evaluation, understanding, and improvement. This includes a new ice fall speed parameterization with riming impact and its test in GFDL AM3, evaluation of model cloud and radiation diurnal and seasonal variation using ARM CMBE data, model ice water content evaluation using ARM cirrus data, and coordination of the TWPICE global model intercomparison. The work illustrates the potential and importance of ARM data for GCM evaluation, understanding, and ultimately, improvement of GCM cloud and radiation parameterizations. Future work includes evaluation and improvement of the new dynamicsPDF cloud scheme and aerosol activation in the GFDL model.

V. Ramaswamy; L. J. Donner; J-C. Golaz; S. A. Klein

2010-06-17T23:59:59.000Z

437

Tropical observability and predictability  

E-Print Network (OSTI)

Many studies have investigated tropical data assimilation in the context of global models or specifically for tropical cyclones, but relatively few have focused on the mesoscale predictability and observability of the ...

Whitcomb, Timothy Robert

2008-01-01T23:59:59.000Z

438

Baroclinically Induced Tropical Cyclogenesis  

Science Conference Proceedings (OSTI)

The authors investigate the transition of numerous subtropical cyclones into late season tropical storms and hurricanes during the 2000 and 2001 Atlantic tropical cyclone seasons. In all transitioning cases (10), the 900–200-hPa wind shear was ...

Christopher A. Davis; Lance F. Bosart

2003-11-01T23:59:59.000Z

439

Aerosols and Ice Particle Size in Tropical Cumulonimbus  

Science Conference Proceedings (OSTI)

A retrieval of ice crystal size near the tops of active deep cumulonimbus clouds (Cb) throughout the Tropics over a 12-yr period is presented based on radiances from the 3.7-?m channel of the Advanced Very High Resolution Radiometer (AVHRR). ...

Steven C. Sherwood

2002-05-01T23:59:59.000Z

440

Effect of Beta Shear on Simulated Tropical Cyclones  

Science Conference Proceedings (OSTI)

Through cloud-resolving simulations, this study examines the effect of ? on the evolution of tropical cyclones (TCs). It is found that the TC simulated on a ? plane with variable Coriolis parameter f is weaker in intensity but larger in size and ...

Juan Fang; Fuqing Zhang

2012-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

1  

NLE Websites -- All DOE Office Websites (Extended Search)

Heating Rates in Mid-Latitude Cirrus Cloud Heating Rates in Mid-Latitude Cirrus Cloud Calculated from Retrieved Cirrus Microphysical Properties Z. Wang Goddard Earth Sciences and Technology Center University of Maryland, Baltimore County College Park, Maryland K. Sassen Department of Meteorology University of Utah Salt Lake City, Utah Introduction Cirrus clouds affect the surface and top-of-atmosphere energy budgets strongly through albedo and greenhouse effects, and can produce large local variations in atmospheric heating with heating at cloud bottom and cooling at cloud top (Liou 1986; Webster and Stephens 1980). Starr and Cox (1985) found that radiative modulation of local buoyancy through horizontal structure affects the structure and bulk properties of cirrus. Ackerman et al. (1988) have indicated that heating rates in tropical anvils are more

442

ARM - Publications: Science Team Meeting Documents  

NLE Websites -- All DOE Office Websites (Extended Search)

A First Look at the Radiative Impact of Tropical Cirrus Systems Encountered A First Look at the Radiative Impact of Tropical Cirrus Systems Encountered During CRYSTAL-FACE Pilewskie, P. (a), Gore, W. (a), Rabbette, M. (b), Howard, S. (b), and Pommier, J. (b), NASA Ames Research Center (a), Bay Area Environmental Research Institute (b) Thirteenth Atmospheric Radiation Measurement (ARM) Science Team Meeting During the 2002 CRYSTAL-FACE experiment we deployed identical solar spectral and broad-band infrared sensors on the ER-2 and CIRPAS Twin Otter in order to characterize the column radiative energy budget in the tropical atmosphere under varying conditions such as thick anvil cirrus, thin sub-visible cirrus, and cloud free conditions. The data are used to determine cirrus and clear sky heating and cooling rates. The solar spectral reflectance and transmittance data are used to infer cloud

443

Sensitivity of Tropical Pacific Convection to Dry Layers at Mid- to Upper Levels: Simulation and Parameterization Tests  

Science Conference Proceedings (OSTI)

Numerical forecast experiments are carried out to investigate the implications of observed moisture variability in the tropical Pacific for deep convection. The study uses a series of quasi-cloud-resolving model forecasts with a triple-nested ...

James A. Ridout

2002-12-01T23:59:59.000Z

444

The Diurnal Variation of Atlantic Ocean Tropical Cyclone aoud DistributionInferred from Geostationary Satellite Infrared Measurements  

Science Conference Proceedings (OSTI)

Satellite-measured equivalent blackbody temperatures of Atlantic Ocean tropical cyclones are used to describe the associated convection and cloud patterns. Average equivalent blackbody temperatures were developed from 538 geostationary satellite ...

Joseph Steranka; Edward B. Rodgers; R. Cecil Gentry

1984-11-01T23:59:59.000Z

445

The Relationship between Precipitation and Lightning in Tropical Island Convection: A C-Band Polarimetric Radar Study  

Science Conference Proceedings (OSTI)

One of the primary scientific objectives of the Maritime Continent Thunderstorm Experiment was to study cloud electrification processes in tropical island convection, in particular, the coupling between ice phase precipitation and lightning ...

Lawrence D. Carey; Steven A. Rutledge

2000-08-01T23:59:59.000Z

446

Some Views On “Hot Towers” after 50 Years of Tropical Field Programs and Two Years of TRMM Data  

Science Conference Proceedings (OSTI)

The “hot tower” hypothesis requires the existence of deep cumulonimbus clouds in the deep Tropics as essential agents, which accomplish the mass and energy transport essential for the maintenance of the general circulation. As the role of the ...

Edward J. Zipser

2003-01-01T23:59:59.000Z

447

A Composite Life Cycle of Nonsquall Mesoscale Convective Systems over the Tropical Ocean. Part I: Kinematic Fields  

Science Conference Proceedings (OSTI)

The wind fields associated with cloud clusters observed during the Global Atmospheric Research Program's Atlantic Tropical Experiment (GATE) are investigated. A compositing procedure is devised to isolate the cluster circulations. Satellite-...

Edward I. Tollerud; Steven K. Esbensen

1985-04-01T23:59:59.000Z

448

The effects of imposed stratospheric cooling on the maximum intensity of tropical cyclones in axisymmetric radiative-convective equilibrium  

Science Conference Proceedings (OSTI)

The effects of stratospheric cooling and sea surface temperature (SST) warming on tropical cyclone (TC) potential intensity (PI) are explored using an axisymmetric cloud-resolving model run to radiative-convective equilibrium (RCE). Almost all ...

Hamish A. Ramsay

449

Nocturnal Continental Low-Level Stratus over Tropical West Africa: Observations and Possible Mechanisms Controlling Its Onset  

Science Conference Proceedings (OSTI)

Some spatiotemporal characteristics and possible mechanisms controlling the onset of the widespread, low-level nocturnal stratiform clouds that formed during May–October 2006 over southern tropical West Africa are investigated using cloudiness ...

Jon M. Schrage; Andreas H. Fink

2012-06-01T23:59:59.000Z

450

A Composite Life Cycle of Nonsquall Mesoscale Convective Systems over the Tropical Ocean. Part II: Heat and Moisture Budgets  

Science Conference Proceedings (OSTI)

The heat and moisture budgets associated with five large nonsquall cloud clusters observed during Phase 3 of the Global Atmospheric Research Program's Atlantic Tropical Experiment (GATE) are investigated. The input data for the budget ...

Steven K. Esbensen; Jough-Tai Wang; Edward I. Tollerud

1988-02-01T23:59:59.000Z

451

Observations of Cloud, Radiation, and Surface Forcing in the Equatorial Eastern Pacific  

Science Conference Proceedings (OSTI)

In this paper the authors report on a study of cloud and surface flux processes in the tropical eastern Pacific Ocean based on a series of ship-based cloud and flux measurements made during fall (1999–2002) and spring (2000–02) maintenance ...

C. W. Fairall; Taneil Uttal; Duane Hazen; Jeffrey Hare; Meghan F. Cronin; Nicholas Bond; Dana E. Veron

2008-02-01T23:59:59.000Z

452

Cloud Computing Operations Research  

Science Conference Proceedings (OSTI)

This paper argues that the cloud computing industry faces many decision problems where operations research OR could add tremendous value. To this end, we provide an OR perspective on cloud computing in three ways. First, we compare the cloud computing ... Keywords: cloud IT, cloud computing, green IT, operations research, supply chain

Ilyas Iyoob, Emrah Zarifoglu, A. B. Dieker

2013-06-01T23:59:59.000Z

453

Retrieval of Cirrus Microphysical Properties with a Suite of Algorithms for Airborne and Spaceborne Lidar, Radar, and Radiometer Data  

Science Conference Proceedings (OSTI)

Algorithms are developed to convert data streams from multiple airborne and spaceborne remote sensors into layer-averaged cirrus bulk microphysical properties. Radiometers such as the Moderate-Resolution Imaging Spectroradiometer (MODIS) observe ...

Yuying Zhang; Gerald G. Mace

2006-12-01T23:59:59.000Z

454

Cloud properties derived from two lidars over the ARM SGP site  

Science Conference Proceedings (OSTI)

[1] Active remote sensors such as lidars or radars can be used with other data to quantify the cloud properties at regional scale and at global scale (Dupont et al., 2009). Relative to radar, lidar remote sensing is sensitive to very thin and high clouds but has a significant limitation due to signal attenuation in the ability to precisely quantify the properties of clouds with a 20 cloud optical thickness larger than 3. In this study, 10-years of backscatter lidar signal data are analysed by a unique algorithm called STRucture of ATmosphere (STRAT, Morille et al., 2007). We apply the STRAT algorithm to data from both the collocated Micropulse lidar (MPL) and a Raman lidar (RL) at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site between 1998 and 2009. Raw backscatter lidar signal is processed and 25 corrections for detector deadtime, afterpulse, and overlap are applied. (Campbell et al.) The cloud properties for all levels of clouds are derived and distributions of cloud base height (CBH), top height (CTH), physical cloud thickness (CT), and optical thickness (COT) from local statistics are compared. The goal of this study is (1) to establish a climatology of macrophysical and optical properties for all levels of clouds observed over the ARM SGP site 30 and (2) to estimate the discrepancies induced by the two remote sensing systems (pulse energy, sampling, resolution, etc.). Our first results tend to show that the MPLs, which are the primary ARM lidars, have a distinctly limited range where all of these cloud properties are detectable, especially cloud top and cloud thickness, but even actual cloud base especially during summer daytime period. According to the comparisons between RL and MPL, almost 50% of situations show a signal to noise ratio too low (smaller than 3) for the MPL in order to detect clouds higher than 7km during daytime period in summer. Consequently, the MPLderived annual cycle of cirrus cloud base (top) altitude is biased low, especially for daylight periods, compared with those derived from the RL data, which detects 5 cloud base ranging from 7.5 km in winter to 9.5 km in summer (and tops ranging from 8.6 to 10.5 km). The optically thickest cirrus clouds (COT>0.3) reach 50% of the total population for the Raman lidar and only 20% for the Micropulse lidar due to the difference of pulse energy and the effect of solar irradiance contamination. A complementary study using the cloud fraction 10 derived from the Micropulse lidar for clouds below 5 km and from the Raman lidar for cloud above 5 km allows for better estimation of the total cloud fraction between the ground and the top of the atmosphere. This study presents the diurnal cycle of cloud fraction for each season in comparisons with the Long et al. (2006) cloud fraction calculation derived from radiative flux analysis.

Dupont, Jean-Charles; Haeffelin, Martial; Morille, Y.; Comstock, Jennifer M.; Flynn, Connor J.; Long, Charles N.; Sivaraman, Chitra; Newsom, Rob K.

2011-02-16T23:59:59.000Z

455

Remote Sensing Observations from MTI Satellites and GMS Over Tropical Island of Nauru  

NLE Websites -- All DOE Office Websites (Extended Search)

Remote Sensing Observations from MTI Satellites and Remote Sensing Observations from MTI Satellites and GMS Over Tropical Island of Nauru W. M. Porch, P. Chylek, and B. Henderson Los Alamos National Laboratory Los Alamos, New Mexico Introduction The observations of island cloud trails have revealed a strong relationship between the character and frequency of occurrence of island cloud trails and the Tropical Ocean Southern Oscillation (MacFarlane et al. 2004 a, b). Island cloud trails from the U.S. Department of Energy's (DOE) Atmospheric and Radiation Measurement (ARM) facility of Nauru persist for more than 50 km (Nordeen et al. 2001) and resemble ship trail clouds found in the Eastern Ocean Margins (Porch et al. 1999). Island trail clouds are much more frequently observed during La Niña periods than El Niño periods (Figure 1). This

456

A Global Climatology of Single-Layer and Overlapped Clouds and their Optical Properties Developed Using a New Algorithm Applied to Terra/MODIS Data  

NLE Websites -- All DOE Office Websites (Extended Search)

Global Climatology of Single-Layer and Overlapped Global Climatology of Single-Layer and Overlapped Clouds and their Optical Properties Developed Using a New Algorithm Applied to Terra/MODIS Data 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 To date, weather satellites are the only tool to measure cloud and climate variables on a global scale, an objective addressed by the International Satellite Cloud Climatology Project (ISCCP) (Rossow and Schiffer 1991; Rossow and Schiffer 1999). However, there is a dearth of information concerning the global climatology of cloud vertical structure and cirrus cloud properties. This is because the often-used

457

Cloud Condensation Nuclei  

Science Conference Proceedings (OSTI)

The state of knowledge of the particles upon which liquid droplets condense to form atmospheric water clouds is presented. The realization of cloud condensation nuclei (CCN) as a distinct aerosol subset originated with the cloud microphysical ...

James G. Hudson

1993-04-01T23:59:59.000Z

458

Forecasting of Supercooled Clouds  

Science Conference Proceedings (OSTI)

Using parameterizations of cloud microphysics, a technique to forecast supercooled cloud events is suggested. This technique can be coupled on the mesoscale with a prognostic equation for cloud water to improve aircraft icing forecasts. The ...

André Tremblay; Anna Glazer; Wanda Szyrmer; George Isaac; Isztar Zawadzki

1995-07-01T23:59:59.000Z

459

Stratocumulus Cloud Field Reflected Fluxes: The Effect of Cloud Shape  

Science Conference Proceedings (OSTI)

Reflected fluxes are calculated for stratocumulus cloud fields as a function of sky cover, cloud aspect ratio, and cloud shape. Cloud liquid water volume is held invariant as cloud shape is varied so that the results can be utilized more ...

R. M. Welch; B. A. Wielicki

1984-11-01T23:59:59.000Z

460

Slide 1  

NLE Websites -- All DOE Office Websites (Extended Search)

Variability of Tropical Cirrus from 2006 TWP-ICE Variability of Tropical Cirrus from 2006 TWP-ICE Junshik Um, Greg M. McFarquhar, and Matt Freer University of Illinois, Urbana IL junum@earth.uiuc.edu 1. Introduction In-situ cloud data acquired during the 2006 Tropical Warm Pool - International Cloud Experiment (TWP-ICE) are used to determine if the microphysical properties of tropical cirrus formed under differing conditions can be characterized in terms of prognostic variables in large-scale models such as temperature and ice water content (IWC) To accomplish this, the spatial variability (horizontal and vertical) of microphysical properties (IWC, habit distribution, size distribution, median mass diameter D mm ) is examined and contrasted for different types of cirrus (convective vs. non- convective; aged vs. fresh),

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Mixing Layer Formation near the Tropopause Due to Gravity Wave–Critical Level Interactions in a Cloud-Resolving Model  

Science Conference Proceedings (OSTI)

A plausible mechanism for the formation of mixing layers in the lower stratosphere above regions of tropical convection is demonstrated numerically using high-resolution, two-dimensional (2D), anelastic, nonlinear, cloud-resolving simulations. ...

Mohamed Moustaoui; Binson Joseph; Hector Teitelbaum

2004-12-01T23:59:59.000Z

462

Understanding the Importance of Microphysics and Macrophysics for Warm Rain in Marine Low Clouds. Part I: Satellite Observations  

Science Conference Proceedings (OSTI)

The importance of macrophysical variables [cloud thickness, liquid water path (LWP)] and microphysical variables (effective radius re, effective droplet concentration Neff) on warm drizzle intensity and frequency across the tropics and subtropics ...

Terence L. Kubar; Dennis L. Hartmann; Robert Wood

2009-10-01T23:59:59.000Z

463

Understanding the Relationships between Lightning, Cloud Microphysics, and Airborne Radar-Derived Storm Structure during Hurricane Karl (2010)  

Science Conference Proceedings (OSTI)

This study explores relationships between lightning, cloud microphysics, and tropical cyclone (TC) storm structure in Hurricane Karl (16 September 2010) using data collected by the NASA DC-8 and Global Hawk (GH) aircraft during NASA’s Genesis and ...

Brad Reinhart; Henry Fuelberg; Richard Blakeslee; Douglas Mach; Andrew Heymsfield; Aaron Bansemer; Stephen L. Durden; Simone Tanelli; Gerald Heymsfield; Bjorn Lambrigtsen

464

ARM - Measurement - Cloud phase  

NLE Websites -- All DOE Office Websites (Extended Search)

property that captures the state o f the hydrometeors within a cloud (liquid, ice, or mixed-phase). This is distinct from cloud type that involves property descriptors...

465

Glossary Term - Cloud Chamber  

NLE Websites -- All DOE Office Websites (Extended Search)

Ceres Previous Term (Ceres) Glossary Main Index Next Term (Composition of the Earth's Atmosphere) Composition of the
Earth's Atmosphere Cloud Chamber A cloud chamber showing the...

466

Seasonal tropical cyclone forecasts  

E-Print Network (OSTI)

Seasonal forecasts of tropical cyclone activity in various regions have been developed since the first attempts in the early 1980s by Neville

Suzana J. Camargo; Anthony G. Barnston; Philip J. Klotzbach; Christopher W. Landsea

2007-01-01T23:59:59.000Z

467

Scanning ARM Cloud Radar Handbook  

SciTech Connect

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.

Widener, K; Bharadwaj, N; Johnson, K

2012-06-18T23:59:59.000Z

468

Objective Determination of Cloud Heights and Radar Reflectivities Using a Combination of Active Remote Sensors at the ARM CART Sites  

Science Conference Proceedings (OSTI)

The U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) Program is deploying sensitive, millimeter-wave cloud radars at its Cloud and Radiation Test Bed (CART) sites in Oklahoma, Alaska, and the tropical western Pacific Ocean. The ...

Eugene E. Clothiaux; Thomas P. Ackerman; Gerald G. Mace; Kenneth P. Moran; Roger T. Marchand; Mark A. Miller; Brooks E. Martner

2000-05-01T23:59:59.000Z

469

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

NLE Websites -- All DOE Office Websites (Extended Search)

ProductsCloud Properties and Radiative Heating Rates for ProductsCloud Properties and Radiative Heating Rates for TWP 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 2002.01.01 - 2012.02.08 Site(s) TWP General Description 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

470

ARM - Publications: Science Team Meeting Documents  

NLE Websites -- All DOE Office Websites (Extended Search)

The Association of the Cirrus Properties Over the Western Tropical Pacific The Association of the Cirrus Properties Over the Western Tropical Pacific with Tropical Deep Convection Deng, M.(a), Mace, G.G.(a), and Soden, B.J.(b), Univesity of Utah (a), Geophysical Fluid Dynamics Laboratory (b) The microphysical and radiative properties of upper tropospheric clouds in the tropics are known to have a substantial influence on climate. Observations from long term cloud radar measurements in the tropics show that upper tropospheric clouds are observed above 10 km as much as 40% of the time depending on location. By combining satellite observations with observations from the tropical ARM site on Nauru and Manus Islands we examine the macro and microphysical properties of these clouds in terms of their association with deep convection. The fundamental questions we will

471

Section 86  

NLE Websites -- All DOE Office Websites (Extended Search)

5 5 Figure 1a. Computed TBB and BTD for effective radius of 10 µm for different cirrus cloud temperatures. Retrieval of Cirrus Cloud Properties from Split Window and 6.7 µm Measurements (IN N) T. Inoue and Y. Mano Meteorological Research Institute / JMA 1-1 Nagamine Tsukuba, Ibaraki 305, Japan Introduction Algorithm A major uncertainty in our present understanding of the Simulated brightness temperatures are computed from the climate system is the effect of clouds. Among these, cirrus radiative transfer equation for given optical thickness and clouds play an especially important role in the global climate cirrus cloud temperatures. Vertical temperature and water system. Since Manabe and Stricker (1964) studied the effect vapor profiles are taken from the U.S. standard tropical

472

In Situ Observation of Cirrus Scattering Phase Functions with 22° and 46° Halos: Cloud Field Study on 19 February 1998  

Science Conference Proceedings (OSTI)

Observations of halos and related phenomena due to ice crystals are commonly reported from ground observations and presented in the literature. Nevertheless, ice crystal characteristics have only been poorly documented from in situ measurements ...

Frederique Auriol; Jean-François Gayet; Guy Febvre; Olivier Jourdan; Laurent Labonnote; Gerard Brogniez

2001-11-01T23:59:59.000Z

473

Global Circuit Model with Clouds  

Science Conference Proceedings (OSTI)

Cloud data from the International Satellite Cloud Climatology Project (ISCCP) database have been introduced into the global circuit model developed by Tinsley and Zhou. Using the cloud-top pressure data and cloud type information, the authors ...

Limin Zhou; Brian A. Tinsley

2010-04-01T23:59:59.000Z

474

Cloud and Precipitation Fields Around Darwin in the Transition Season  

NLE Websites -- All DOE Office Websites (Extended Search)

and Precipitation Fields Around Darwin and Precipitation Fields Around Darwin in the Transition Season P. T. May Bureau of Meteorology Research Centre Melbourne, 3001, Victoria, Australia Introduction An interesting, and very relevant question, for the Atmospheric Radiation Measurement (ARM) Program is how cloud characteristics and their seasonal and diurnal variation changes across the tropics. In particular, how does he cloud field around the new SRCS site compare with nearby regions. Thus, the aim of this study is to look at the characteristics of clouds and precipitation in the area around Darwin and to compare the cloud statistics estimated from geostationary meteorological satellite (GMS) satellite data with other nearby regions. Towards this end, GMS satellite imagery and radar data from

475

Cloud Computing Forum & Workshop II  

Science Conference Proceedings (OSTI)

Cloud Computing Forum & Workshop II. Purpose: On May 20, 2010, NIST hosted the first Cloud Computing Forum & Workshop. ...

2013-08-07T23:59:59.000Z

476

Diurnal Variations and Modulation by Easterly Waves of the Size Distribution of Convective Cloud Clusters over West Africa and the Atlantic Ocean  

Science Conference Proceedings (OSTI)

Using Metecosat satellite data in the atmospheric infrared window, the authors study short time-scale fluctuations of the size distribution of tropical convective cloud clusters for July to September 1989. A cluster at a given brightness-...

L. A. Toledo Machado; J-Ph Duvel; M. Desbois

1993-01-01T23:59:59.000Z

477

Cloud-Cluster-Scale Circulations and the Vorticity Budget of Synoptic-Scale Waves Over the Eastern Atlantic Intertropical Convergence Zone  

Science Conference Proceedings (OSTI)

Objectively analyzed upper-air winds over the intertropical convergence zone of the eastern tropical Atlantic are separated into components representing the mean flow, westward moving synoptic-scale waves and cloud-cluster-scale motions during ...

Steven K. Esbensen; Edward I. Tollerud; Jan-Hwa Chu

1982-11-01T23:59:59.000Z

478

ISCCP Cloud Algorithm Intercomparison  

Science Conference Proceedings (OSTI)

The International Satellite Cloud Climatology Project (ISCCP) will provide a uniform global climatology of satellite-measured radiances and derive an experimental climatology of cloud radiative properties from these radiances. A pilot study to ...

W. B. Rossow; F. Mosher; E. Kinsella; A. Arking; M. Desbois; E. Harrison; P. Minnis; E. Ruprecht; G. Seze; C. Simmer; E. Smith

1985-09-01T23:59:59.000Z

479

ARM - Measurement - Cloud type  

NLE Websites -- All DOE Office Websites (Extended Search)

type 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 type Cloud type such as...

480

Entrainment in Cumulus Clouds  

Science Conference Proceedings (OSTI)

Entrainment of dry air into cumulus clouds influences the development of the clouds in a major way. The many aspects of the entrainment process are examined in this paper by critically reviewing the literature from the time when investigations ...

Alan M. Blyth

1993-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical cirrus clouds" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Automated cloud resource orchestration  

Science Conference Proceedings (OSTI)

Realizing Infrastructure-as-a-Service (IaaS) cloud requires a control platform for orchestrating the provisioning, configuration, management and decommissioning of a distributed set of diverse cloud resources (i.e., compute, storage, network) serving ...

Changbin Liu / Boon Thau Loo

2012-01-01T23:59:59.000Z

482

North Australian Cloud Lines  

Science Conference Proceedings (OSTI)

A satellite classification and climatology of propagating mesoscale cloud fines in northern Australia is presented. These cloud fines range from long, narrow lines of shallow convection to extensive deep convective squall lines with mesoscale ...

W. Drosdowsky; G. J. Holland

1987-11-01T23:59:59.000Z

483

Cloud Computing at NERSC  

NLE Websites -- All DOE Office Websites (Extended Search)

Cloud Computing Energy Efficient Computing Exascale Computing Performance & Monitoring Tools Petascale Initiative Science Gateway Development Storage and IO Technologies Testbeds...

484

Computing and Partitioning Cloud Feedbacks Using Cloud Property Histograms. Part I: Cloud Radiative Kernels  

Science Conference Proceedings (OSTI)

This study proposes a novel technique for computing cloud feedbacks using histograms of cloud fraction as a joint function of cloud-top pressure (CTP) and optical depth (?). These histograms were generated by the International Satellite Cloud ...

Mark D. Zelinka; Stephen A. Klein; Dennis L. Hartmann

2012-06-01T23:59:59.000Z

485

Rope Cloud over Land  

Science Conference Proceedings (OSTI)

Satellite imagery is used to document several rope clouds over the southeastern Unites States. Surface and upper-air data are examined for one of the rope clouds and possible reasons for the development and maintenance of this type cloud line are ...

Von S. Woods

1983-03-01T23:59:59.000Z

486

User Centric Community Clouds  

Science Conference Proceedings (OSTI)

With the evolution in cloud technologies, users are becoming acquainted with seamless service provision. Nevertheless, clouds are not a user centric technology, and users become completely dependent on service providers. We propose a novel concept for ... Keywords: Cloud infrastructure, Identity management, User-centric systems

João Paulo Barraca; Alfredo Matos; Rui L. Aguiar

2011-05-01T23:59:59.000Z

487

A Community Atmosphere Model with Superparameterized Clouds  

SciTech Connect

In 1999, National Center for Atmospheric Research (NCAR) scientists Wojciech Grabowski and Piotr Smolarkiewicz created a "multiscale" atmospheric model in which the physical processes associated with clouds were represented by running a simple high-resolution model within each grid column of a lowresolution global model. In idealized experiments, they found that the multiscale model produced promising simulations of organized tropical convection, which other models had struggled to produce. Inspired by their results, Colorado State University (CSU) scientists Marat Khairoutdinov and David Randall created a multiscale version of the Community Atmosphere Model (CAM). They removed the cloud parameterizations of the CAM, and replaced them with Khairoutdinov's high-resolution cloud model. They dubbed the embedded cloud model a "super-parameterization," and the modified CAM is now called the "SP-CAM." Over the next several years, many scientists, from many institutions, have explored the ability of the SP-CAM to simulate tropical weather systems, the day-night changes of precipitation, the Asian and African monsoons, and a number of other climate processes. Cristiana Stan of the Center for Ocean-Land-Atmosphere Interactions found that the SP-CAM gives improved results when coupled to an ocean model, and follow-on studies have explored the SP-CAM's utility when used as the atmospheric component of the Community Earth System Model. Much of this research has been performed under the auspices of the Center for Multiscale Modeling of Atmospheric Processes, a National Science Foundation (NSF) Science and Technology Center for which the lead institution is CSU.

Randall, David; Branson, Mark; Wang, Minghuai; Ghan, Steven J.; Craig, Cheryl; Gettelman, A.; Edwards, Jim

2013-06-18T23:59:59.000Z

488

A Tropical Cyclone Genesis Parameter for the Tropical Atlantic  

Science Conference Proceedings (OSTI)

A parameter to evaluate the potential for tropical cyclone formation (genesis) in the North Atlantic between Africa and the Caribbean islands is developed. Climatologically, this region is the source of about 40% of the Atlantic basin tropical ...

Mark DeMaria; John A. Knaff; Bernadette H. Connell

2001-04-01T23:59:59.000Z

489

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

SciTech Connect

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.

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

2011-02-01T23:59:59.000Z

490

Tropical Cloud Feedbacks and Natural Variability of Climate  

Science Conference Proceedings (OSTI)

Simulations of natural variability by two GCMs are examined. One GCM is a sector model, allowing relatively rapid integration without simplification of the model physics, which would potentially exclude mechanisms of variability. Two mechanisms ...

R. L. Miller; A. D. Del Genio

1994-09-01T23:59:59.000Z

491

ARM - Field Campaign - Tropical Warm Pool - International Cloud...  

NLE Websites -- All DOE Office Websites (Extended Search)

the US DOE ARM project, the Bureau of Meteorology, NASA, the European Commission DG RTD-1.2 and several United States, Australian, Canadian and European Universities. TWP-ICE...

492

Turbulent molecular clouds  

E-Print Network (OSTI)

Stars form within molecular clouds but our understanding of this fundamental process remains hampered by the complexity of the physics that drives their evolution. We review our observational and theoretical knowledge of molecular clouds trying to confront the two approaches wherever possible. After a broad presentation of the cold interstellar medium and molecular clouds, we emphasize the dynamical processes with special focus to turbulence and its impact on cloud evolution. We then review our knowledge of the velocity, density and magnetic fields. We end by openings towards new chemistry models and the links between molecular cloud structure and star--formation rates.

Hennebelle, Patrick

2012-01-01T23:59:59.000Z

493

Annual and Nonseasonal Variability of Monthly Low-Level Wind Fields over the Southeastern Tropical Pacific  

Science Conference Proceedings (OSTI)

The time and space variability of low-level winds over the Southeast Tropical Pacific (SETP) region is described for the 6-year period 1974–80. The data set consists of monthly averaged low-level cloud-motion vector winds supplemented by coastal ...

David B. Enfield

1981-10-01T23:59:59.000Z

494

Global Distribution of Tropical Deep Convection: Different Perspectives from TRMM Infrared and Radar Data  

Science Conference Proceedings (OSTI)

Cold cloud features (CCFs) are defined by grouping six full years of Tropical Rainfall Measuring Mission (TRMM) infrared pixels with brightness temperature at 10.8-?m wavelength (TB11) less than or equal to 210 and 235 K. Then the precipitation ...

Chuntao Liu; Edward J. Zipser; Stephen W. Nesbitt

2007-02-01T23:59:59.000Z

495

A Trajectory Analysis of Tropical Upper-Tropospheric Moisture and Convection  

Science Conference Proceedings (OSTI)

It is shown that the distribution of upper-tropospheric humidity (UTH) in the cloud-free Tropics can be simulated with a simple model in which air expelled from moist convective regions is dried by subsidence along its trajectory. The ...

Eric P. Salathé Jr.; Dennis L. Hartmann

1997-10-01T23:59:59.000Z

496

Rapid Scan Views of Convectively Generated Mesovortices in Sheared Tropical Cyclone Gustav (2002)  

Science Conference Proceedings (OSTI)

On 9–10 September 2002, multiple mesovortices were captured in great detail by rapid scan visible satellite imagery in subtropical, then later, Tropical Storm Gustav. These mesovortices were observed as low-level cloud swirls while the low-level ...

Eric A. Hendricks; Michael T. Montgomery

2006-12-01T23:59:59.000Z

497

On the Use of Satellite-Derived Heating Rates for Data Assimilation within the Tropics  

Science Conference Proceedings (OSTI)

The HIRS instrument on the NOAA polar orbiting satellites is used to obtain coverage of outward-going longwave radiation across the global tropics and subtropics four times a day. Fractional coverage of cold cloud is obtained from this, which is ...

William A. Heckley; Graeme Kelly; Michael Tiedtke

1990-09-01T23:59:59.000Z

498

»ÃµÆƬ 1  

NLE Websites -- All DOE Office Websites (Extended Search)

the Radiative Forcings the Radiative Forcings of Thin Cirrus in the Tropical Atmosphere Using AIRS/ARM Data Qing Yue, K. N. Liou, and Y. Gu University of California, Los Angeles, Los Angeles, California Introduction and Motivation * Cirrus clouds are the highest clouds in the troposphere, regularly cover 20-30% of the globe (Liou 1986) and have been found to have a high frequency of occurrence (e. g. Wylie et al. 2004). * Given the high location, large coverage, and frequent occurrence, the effect of cirrus clouds on the energy balance of the earth-atmosphere system is a critically important research topic. * The Fu-Liou (1993, Fu 1996, Fu et al. 1998) parameterization of cirrus clouds radiative properties has been upgraded by using a model of mixed ice crystal habits. Sensitivity studies has been carried

499

Study of Mechanisms of Aerosol Indirect Effects on Glaciated Clouds: Progress during the Project Final Technical Report  

SciTech Connect

This 3-year project has studied how aerosol pollution influences glaciated clouds. The tool applied has been an 'aerosol-cloud model'. It is a type of Cloud-System Resolving Model (CSRM) modified to include 2-moment bulk microphysics and 7 aerosol species, as described by Phillips et al. (2009, 2013). The study has been done by, first, improving the model and then performing sensitivity studies with validated simulations of a couple of observed cases from ARM. These are namely the Tropical Warm Pool International Cloud Experiment (TWP-ICE) over the tropical west Pacific and the Cloud and Land Surface Interaction Campaign (CLASIC) over Oklahoma. During the project, sensitivity tests with the model showed that in continental clouds, extra liquid aerosols (soluble aerosol material) from pollution inhibited warm rain processes for precipitation production. This promoted homogeneous freezing of cloud droplets and aerosols. Mass and number concentrations of cloud-ice particles were boosted. The mean sizes of cloud-ice particles were reduced by the pollution. Hence, the lifetime of glaciated clouds, especially ice-only clouds, was augmented due to inhibition of sedimentation and ice-ice aggregation. Latent heat released from extra homogeneous freezing invigorated convective updrafts, and raised their maximum cloud-tops, when aerosol pollution was included. In the particular cases simulated in the project, the aerosol indirect effect of glaciated clouds was twice than of (warm) water clouds. This was because glaciated clouds are higher in the troposphere than water clouds and have the first interaction with incoming solar radiation. Ice-only clouds caused solar cooling by becoming more extensive as a result of aerosol pollution. This 'lifetime indirect effect' of ice-only clouds was due to higher numbers of homogeneously nucleated ice crystals causing a reduction in their mean size, slowing the ice-crystal process of snow production and slowing sedimentation. In addition to the known indirect effects (glaciation, riming and thermodynamic), new indirect effects were discovered and quantified due to responses of sedimentation, aggregation and coalescence in glaciated clouds to changing aerosol conditions. In summary, the change in horizontal extent of the glaciated clouds ('lifetime indirect effects'), especially of ice-only clouds, was seen to be of higher importance in regulating aerosol indirect effects than changes in cloud properties ('cloud albedo indirect effects').

Phillips, Vaughan T. J.

2013-10-18T23:59:59.000Z

500

Cloud Properties Working Group Low Clouds Update  

NLE Websites -- All DOE Office Websites (Extended Search)

Cloud Properties Working Group Cloud Properties Working Group Low Clouds Update Low Clouds Update Jennifer Comstock Jennifer Comstock Dave Turner Dave Turner Andy Andy Vogelmann Vogelmann Instruments Instruments 90/150 GHz microwave radiometer 90/150 GHz microwave radiometer Deployed during COPS AMF Deployed during COPS AMF Exploring calibration w/ DPR ( Exploring calibration w/ DPR ( Crewell Crewell & & L L ö ö hnert hnert ) ) See COPS Breakout, Wednesday evening See COPS Breakout, Wednesday evening 183 GHz (GVR) deployed at the NSA 183 GHz (GVR) deployed at the NSA Neural network algorithm to retrieve PWV & LWP (Maria Neural network algorithm to retrieve PWV & LWP (Maria Cadeddu Cadeddu ) ) Potential VAP candidate (RPWG) Potential VAP candidate (RPWG)