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Note: This page contains sample records for the topic "mase-marine stratus experiment-pt" 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
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1

Microsoft PowerPoint - ARM08_hguo_080229.ppt  

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

model, Meteorol. Atmos. Phys., 82, 97-137, 2003. TAKE ONE 1. Introduction 2. MASRAD (Marine Stratus Radiation Aerosol and Drizzle)MASE (Marine Stratus Stratocumulus...

2

Infrared Propagation Modeling beneath Marine Stratus Clouds  

Science Conference Proceedings (OSTI)

Airborne measurements of aerosol size distributions are used to determine the vertical profiles of infrared (IR) extinction and absorption coefficients and asymmetry factors in eight different maritime stratus cloud regimes during unstable ...

H. G. Hughes; C. R. Zeisse

2000-04-01T23:59:59.000Z

3

Effects of CCN Concentrations on Stratus Clouds  

Science Conference Proceedings (OSTI)

Comparisons between cloud-base CCN concentrations and cloud droplet concentrations in stratus clouds over San Diego and 100 km out to sea showed a positive correlation. The supersaturation in these clouds, as derived from the matching of the CCN ...

James G. Hudson

1983-02-01T23:59:59.000Z

4

Stratus Surge Prediction along the Central California Coast  

Science Conference Proceedings (OSTI)

A simple decision-tree forecast scheme to predict the south-north development or movement of stratus along the central California coast is developed and tested. Known as stratus surges, these mesoscale events are infrequently observed along the ...

Peter Felsch; Woodrow Whitlatch

1993-06-01T23:59:59.000Z

5

Satellite Determination of Stratus Cloud Microphysical Properties  

Science Conference Proceedings (OSTI)

Satellite measurements of liquid water path from SSM/I, broadband albedo from ERBE, and cloud characteristics from ISCCP are used to study stratus regions. An average cloud liquid water path of 0.120 0.032 kg m?2 is derived by dividing the ...

Paquita Zuidema; Dennis L. Hartmann

1995-06-01T23:59:59.000Z

6

sgp_stratus_poster_v1.0.ppt  

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

overlaid on the LES profiles. *This stratus case was not accompanied by consistent subsidence and slowly varying advective forcings typical of a marine barotropic atmosphere....

7

ARM - Field Campaign - MArine Stratus Radiation Aerosol and Drizzle  

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

govCampaignsMArine Stratus Radiation Aerosol and Drizzle (MASRAD) IOP govCampaignsMArine Stratus Radiation Aerosol and Drizzle (MASRAD) IOP Campaign Links Science Plan AMF Point Reyes Website AMF Point Reyes Data Plots Related Campaigns MASRAD: Pt. Reyes Stratus Cloud and Drizzle Study 2005.07.07, Coulter, AMF MASRAD: Cloud Condensate Nuclei Chemistry Measurements 2005.07.01, Berkowitz, AMF MASRAD - Aerosol Optical Properties 2005.06.29, Strawa, AMF MASRAD:Sub-Micron Aerosol Measurements 2005.06.20, Wang, AMF MASRAD: Cloud Study from the 2NFOV at Pt. Reyes Field Campaign 2005.06.02, Wiscombe, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : MArine Stratus Radiation Aerosol and Drizzle (MASRAD) IOP 2005.03.14 - 2005.09.14 Website : http://www.arm.gov/sites/amf/pye/ Lead Scientist : Mark Miller

8

Physical Processes within the Nocturnal Stratus-topped Boundary Layer  

Science Conference Proceedings (OSTI)

Within the stratus-topped boundary layer many physical processes are involved: longwave radiation cooling, entrainment, latent heating, surface heating, solar heating, drizzling, etc. How all processes combine to maintain the turbulence within ...

Chin-Hoh Moeng; Shaohua Shen; David A. Randall

1992-12-01T23:59:59.000Z

9

Interannual Variability of the Upper Ocean in the Southeast Pacific Stratus Cloud Region  

Science Conference Proceedings (OSTI)

Persistent stratus/stratocumulus cloud decks in the southeast Pacific near the coasts of Peru and northern Chile play an important role in regional and global climate variability. Interannual variability of the upper ocean under stratus cloud ...

Toshiaki Shinoda; Jialin Lin

2009-10-01T23:59:59.000Z

10

Continental Liquid-phase Stratus Clouds at SGP: Meteorological Influences  

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

Continental Liquid-phase Stratus Clouds at SGP: Meteorological Influences Continental Liquid-phase Stratus Clouds at SGP: Meteorological Influences and Relationship to Adiabacity Kim, Byung-Gon Kangnung National University Schwartz, Stephen Brookhaven National Laboratory Miller, Mark Brookhaven National Laboratory Min, Qilong State University of New York at Albany Category: Cloud Properties The microphysical properties of continental stratus clouds observed over SGP appear to be substantially influenced by micrometeorological conditions, such as static stability and updraft velocity. These influences may contribute to the observed weak correlation of aerosol light scattering coefficient with cloud-drop effective radius [Kim et al., JGR, 2003], although aerosol light scattering coefficient is not necessarily the most suitable surrogate aerosol property for number concentration of cloud

11

Droplet Spectra Observed in Marine Stratus Cloud Layers  

Science Conference Proceedings (OSTI)

Airborne measurements of the water droplet spectra n(r) (r is radius) (0.23 ? r ? 150 ?m) were made at about 14 levels in stratus layers during May and August 1981, 130 km SW of San Diego. All May days were found to be associated with air masses ...

V. Ray Noonkester

1984-03-01T23:59:59.000Z

12

Seeding Tests on Supercooled Stratus Using Vertical Fall Pyrotechnics  

Science Conference Proceedings (OSTI)

In Michigan in early 1977, an experiment was conducted to test the ability of silver iodide (AgI) ice nucleus curtains generated by vertical-fall pyrotechnics to produce clearings in supercooled stratus. A second objective of the experiment was ...

Joe L. Sutherland; John R. Thompson; Don A. Griffith; Bruce Kunkel

1982-02-01T23:59:59.000Z

13

Ozone Destruction in Continental Stratus Clouds: An Aircraft Case Study  

Science Conference Proceedings (OSTI)

Apparent depletion of ozone in a cold (0C), continental stratus cloud system was observed during in situ data collection on 30 April 1994 at the Department of Energy Clouds and Radiation Test Bed site in northern Oklahoma. Analyses of the ...

Zhien Wang; Kenneth Sassen

2000-06-01T23:59:59.000Z

14

An Examination of the Breakup of Marine Stratus: a Three-Dimensional Numerical Investigation  

Science Conference Proceedings (OSTI)

Cloud top entrainment instability, as a mechanism for the breakup of marine stratus, is examined with a three-dimensional, planetary boundary layer (PBL) model. Specifically, we examine the criterion developed by Randall and Deardorff; this ...

Paul M. Tag; Steven W. Payne

1987-01-01T23:59:59.000Z

15

MODIS Observations of Ship Tracks in Summertime Stratus off the West Coast of the United States  

Science Conference Proceedings (OSTI)

Three years of 1-km Moderate Resolution Imaging Spectroradiometer (MODIS) observations for morning (Terra) and afternoon (Aqua) summertime marine stratus off the west coast of the United States were analyzed to determine the response of the ...

Matthew S. Segrin; James A. Coakley Jr.; William R. Tahnk

2007-12-01T23:59:59.000Z

16

Advances in Predicting Continental Low Stratus with a Regional NWP Model  

Science Conference Proceedings (OSTI)

In the eastern Alpine region, subinversion cloudiness associated with elevated temperature inversions is a frequent phenomenon in autumn and winter, which often persists for several days. Although the prediction of fog and low stratus by ...

Alexander Kann; Harald Seidl; Christoph Wittmann; Thomas Haiden

2010-02-01T23:59:59.000Z

17

Turbulence Structure of Arctic Stratus Clouds Derived from Measurements and Calculations  

Science Conference Proceedings (OSTI)

Results are presented from a detailed case study of an Arctic stratus cloud over the Fram Strait that is based on aircraft measurements and model calculations. The measurements have been performed during MIZEX 1984 (Marginal Ice Zone Experiment) ...

Jrg E. Finger; Peter Wendling

1990-06-01T23:59:59.000Z

18

Large-Eddy Simulation of a Stratus-Topped Boundary Layer. Part I: Structure and Budgets  

Science Conference Proceedings (OSTI)

The structure of a stratus-topped boundary layer is observed through large-eddy simulation which includes the interaction of longwave radiation and turbulence processes. This simulated boundary layer has a relatively warm and dry overlying ...

Chin-Hoh Moeng

1986-12-01T23:59:59.000Z

19

Observational and Theoretical Studies of Solar Radiation in Arctic Stratus Clouds  

Science Conference Proceedings (OSTI)

A series of clouds-radiation experiments was carried out in June 1980 in Arctic stratus clouds occurring over the Beaufort Sea using the NCAR Electra aircraft. This paper is an analysis of the hemispheric radiation fields obtained with Eppley ...

G. F. Herman; J. A. Curry

1984-01-01T23:59:59.000Z

20

CCN and Vertical Velocity Influences on Droplet Concentrations and Supersaturations in Clean and Polluted Stratus Clouds  

Science Conference Proceedings (OSTI)

Cloud microphysics and CCN measurements from two marine stratus cloud projects are presented and analyzed. Results show that the increase of cloud droplet concentrations (Nc) withCCN concentrations (NCCN) rolls off for NCCN at 1% supersaturation (...

James G. Hudson; Stephen Noble

Note: This page contains sample records for the topic "mase-marine stratus experiment-pt" 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

Influence of Humidified Aerosol on Lidar Depolarization Measurements below Ice-Precipitating Arctic Stratus  

Science Conference Proceedings (OSTI)

Lidar measurements obtained during the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment under a mixed-phase stratus cloud that was lightly precipitating ice show a range of surprisingly low depolarization ratios (4%23%), despite an ...

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

2011-10-01T23:59:59.000Z

22

A Potential Role for Immersion Freezing in Arctic Mixed-Phase Stratus  

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

Potential Role for Immersion Freezing in Arctic Mixed-Phase Stratus Potential Role for Immersion Freezing in Arctic Mixed-Phase Stratus Gijs de Boer, Edwin W. Eloranta, Tempei Hashino, and Gregory J. Tripoli The University of Wisconsin - Madison (1) Introduction Ice formation appears to a dominant factor controlling the lifecycle of Arctic mixed-phase clouds. To date, our understanding of ice formation in these long-lasting cloud structures does not explain the formation of observed ice amounts. Particularly puzzling are observa-

23

Radiative Impacts on the Growth of a Population of Drops within Simulated Summertime Arctic Stratus  

Science Conference Proceedings (OSTI)

The impact of solar heating and infrared cooling on the growth of a population of drops is studied with two numerical modeling frameworks. An eddy-resolving model (ERM) simulation of Arctic stratus clouds is used to generate a dataset of 500 ...

Jerry Y. Harrington; Graham Feingold; William R. Cotton

2000-03-01T23:59:59.000Z

24

profiles of optical Extinction Coefficients Calculated from Droplet Spectra Observed in Marine Stratus Cloud Layers  

Science Conference Proceedings (OSTI)

Airborne measurements of droplet spectra n(r) where r is droplet radius were made in stratus cloud layers over the ocean 130 km southwest of San Diego. Optical extinction coefficients ?e were calculated at selected wavelengths (?= 0.53, 3.75 and ...

V. Ray Noonkester

1985-06-01T23:59:59.000Z

25

Formation and maintenance of nocturnal low-level stratus over the southern West African monsoon region during AMMA 2006  

Science Conference Proceedings (OSTI)

The southern parts of West Africa are frequently covered by an extensive deck of shallow, low (200 400 m above ground) stratus or stratocumulus clouds during the summer monsoon season. These clouds usually form at night in association with a ...

Robert Schuster; Andreas H. Fink; Peter Knippertz

26

Dynamic and thermodynamic relations of distinctive stratus clouds on the lee side of the Tibetan Plateau in the cold season  

Science Conference Proceedings (OSTI)

Given the large discrepancies that exist in the climate models for shortwave cloud forcing over eastern China (EC), the dynamic (vertical motion and horizontal circulation) and thermodynamic (stability) relations of stratus clouds and the ...

Yi Zhang; Rucong Yu; Jian Li; Weihua Yuan; Minghua Zhang

27

Aerosol Size Spectra in a Convective Marine Layer with Stratus: Results of Airborne Measurements near San Nicolas Island, California  

Science Conference Proceedings (OSTI)

Airborne measurements of the aerosol size spectra n (r) (r is radius) were made in a vertical plane extending northeastward 18 km from San Nicolas Island, California. Thin, patchy, stratus clouds were present in a deepening convective marine ...

V. Ray Noonkester

1981-09-01T23:59:59.000Z

28

Analysis of Aerosol Indirect Effects in California Coastal Stratus and Fog  

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

Analysis of Aerosol Indirect Effects in California Coastal Stratus and Fog Analysis of Aerosol Indirect Effects in California Coastal Stratus and Fog Miller, Mark Brookhaven National Laboratory Kollias, Pavlos Brookhaven National Laboratory Bartholomew, Mary Jane Brookhaven National Laboratory Daum, Peter Brookhaven National Laboratory Dunn, Maureen Brookhaven National Laboratory Jensen, Michael Brookhaven National Laboratory Liu, Yangang Brookhaven National Laboratory Vogelmann, Andrew Brookhaven National Laboratory Andrews, Betsy NOAA/CMDL Ogren, John NOAA/CMDL Turner, David University of Wisconsin-Madison Category: Field Campaigns Impacts of aerosol indirect effects are considered too uncertain for inclusion in reports issued by the Intergovernmental Panel on Climate Change. A major reason for this uncertainty is an insufficient physical

29

Application Of Microholography for Ground-based In Situ Measurements in Stratus Cloud Layers: A Case Study  

Science Conference Proceedings (OSTI)

A holographic droplet and aerosol recording system (HODAR) has been designed and operated in situ in a low-level stratus cloud layer adopting the Fraunhofer in-line technique to measure sizes and velocity vectors of cloud droplets as well as to ...

Stephan Borrmann; Ruprecht Jaenicke

1993-06-01T23:59:59.000Z

30

Formation and Maintenance of Nocturnal Low-Level Stratus over the Southern West African Monsoon Region during AMMA 2006  

Science Conference Proceedings (OSTI)

The southern parts of West Africa are frequently covered by an extensive deck of shallow, low (200400 m AGL) stratus or stratocumulus clouds during the summer monsoon. These clouds usually form at night in association with a nocturnal low-level ...

Robert Schuster; Andreas H. Fink; Peter Knippertz

2013-08-01T23:59:59.000Z

31

Arctic Stratus Cloud Properties and Radiative Forcing Derived from Ground-Based Data Collected at Barrow, Alaska  

Science Conference Proceedings (OSTI)

A record of single-layer and overcast low-level Arctic stratus cloud properties has been generated using data collected from May to September 2000 at the Atmospheric Radiation Measurement (ARM) North Slope of Alaska (NSA) (71.3N, 156.6W) site ...

Xiquan Dong; Gerald G. Mace

2003-02-01T23:59:59.000Z

32

Equations Governing Space-Time Variability of Liquid Water Path in Stratus Clouds  

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

Equations Governing Space-Time Variability of Equations Governing Space-Time Variability of Liquid Water Path in Stratus Clouds K. Ivanova Pennsylvania State University University Park, Pennsylvania T. P. Ackerman Pacific Northwest National Laboratory Richland, Washington M. Ausloos University of Liège B-4000 Liège, Belgium Abstract We present a method on how to derive an underlying mathematical (statistical or model free) equation for a liquid water path (LWP) signal directly from empirical data. The evolution of the probability density functions (PDFs) from small to large time scales is explicitly derived in the framework of Fokker-Planck equation. A drift and a diffusion term describing the deterministic and stochastic influences on the non-Gaussian fat tails of the liquid water probability distributions are obtained from

33

Forecast-Based Decision Support for San Francisco International Airport: A NextGen Prototype System That Improves Operations during Summer Stratus Season  

E-Print Network (OSTI)

During summer, marine stratus encroaches into the approach to San Francisco International Airport (SFO) bringing low ceilings. Low ceilings restrict landings and result in a high number of arrival delays, thus impacting ...

Reynolds, David W.

34

Sea Surface Temperature Biases under the Stratus Cloud Deck in the Southeast Pacific Ocean in 19 IPCC AR4 Coupled General Circulation Models  

Science Conference Proceedings (OSTI)

This study examines systematic biases in sea surface temperature (SST) under the stratus cloud deck in the southeast Pacific Ocean and upper-ocean processes relevant to the SST biases in 19 coupled general circulation models (CGCMs) participating ...

Yangxing Zheng; Toshiaki Shinoda; Jia-Lin Lin; George N. Kiladis

2011-08-01T23:59:59.000Z

35

Forecast-Based Decision Support for San Francisco International Airport: A NextGen Prototype System That Improves Operations during Summer Stratus Season  

Science Conference Proceedings (OSTI)

During summer, marine stratus encroaches into the approach to San Francisco International Airport (SFO) bringing low ceilings. Low ceilings restrict landings and result in a high number of arrival delays, thus impacting the National Air Space (NAS). These ...

David W. Reynolds; David A. Clark; F. Wesley Wilson; Lara Cook

2012-10-01T23:59:59.000Z

36

A Potential Role for Immersion Freezing in Arctic Mixed-Phase Stratus Gijs de Boer,Edwin W.Eloranta,Tempei Hashino,and Gregory J.Tripoli  

E-Print Network (OSTI)

to a dominant factor controlling the lifecycle of Arctic mixed-phase clouds. To date, our understanding of ice Stratus from M-PACE Mixed-Phase Layer Ice Precipitation "Bursts" Time (UT) Altitude(km) Lidar backscatter. - Additionally, Shupe illustrated that ice water content and liquid water content seem to vary in phase with each

Eloranta, Edwin W.

37

392 JOURNAL OF CLIMATE VOLUME 19 Surface Cloud Forcing in the East Pacific Stratus Deck/Cold Tongue/ITCZ Complex*  

E-Print Network (OSTI)

Data from the Eastern Pacific Investigation of Climate Studies (EPIC) mooring array are used to evaluate the annual cycle of surface cloud forcing in the far eastern Pacific stratus cloud deck/cold tongue/ intertropical convergence zone complex. Data include downwelling surface solar and longwave radiation from 10 EPIC-enhanced Tropical Atmosphere Ocean (TAO) moorings from 8S, 95W to 12N, 95W, and the Woods Hole Improved Meteorology (IMET) mooring in the stratus cloud deck region at 20S, 85W. Surface cloud forcing is defined as the observed downwelling radiation at the surface minus the clear-sky value. Solar cloud forcing and longwave cloud forcing are anticorrelated at all latitudes from 12N to 20S: clouds tended to reduce the downward solar radiation and to a lesser extent increase the downward longwave radiation at the surface. The relative amount of solar radiation reduction and longwave increase depends upon cloud type and varies with latitude. A statistical relationship between solar and longwave surface cloud forcing is developed for rainy and dry periods and for the full record length in six latitudinal regions: northeast tropical warm pool, ITCZ, frontal zone, cold tongue, southern, and stratus deck regions. The buoy cloud forcing observations and empirical relations are compared with the International Satellite Cloud Climatology Project (ISCCP) radiative flux data (FD) dataset and are used as benchmarks to

Meghan F. Cronin; Nicholas A. Bond; Christopher W. Fairall; Robert A. Weller

2004-01-01T23:59:59.000Z

38

Microphysical Contrasts in Atlantic Stratus  

Science Conference Proceedings (OSTI)

Measurements of a mid-Atlantic clean and polluted cloud are presented. The cleaner cloud had lower concentrations of larger droplets with a broader spectrum and more drizzle drops. The first two characteristics are attributed to the lower cloud ...

James G. Hudson; Hongguo Li

1995-08-01T23:59:59.000Z

39

Cloud Microphysical Relationships in California Marine Stratus  

Science Conference Proceedings (OSTI)

Cloud microphysical measurements off the southern California coast are presented and compared with in situ airborne measurements of cloud condensation nuclei (CCN) spectra. Large-scale variations in cloud droplet concentrations were due to CCN ...

James G. Hudson; Gunilla Svensson

1995-12-01T23:59:59.000Z

40

Composite Structure of Plumes in Stratus-topped Boundary Layers  

Science Conference Proceedings (OSTI)

Knowledge of convective plumes within the clear convective boundary layer (CBL) is quite advanced owing to direct measurements, tank experiments, and large-eddy simulation studies. As a result, modeling of the CBL is relatively successful. ...

Chin-Hoh Moeng; Ulrich Schumann

1991-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "mase-marine stratus experiment-pt" 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

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

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

and Artifact Detection with Semi-Discrete Wavelet Analyses A. B. Davis Space and Remote Sensing Sciences Group Los Alamos National Laboratory Los Alamos, New Mexico N. P....

42

ARM - Field Campaign - MASRAD: Pt. Reyes Stratus Cloud and Drizzle...  

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

which in combination with aircraft in-situ measurements aid in determining the modification of aerosols by cloud processes. In addition the sodar and profiler provide...

43

The Retrieval of Stratus Cloud Droplet Effective Radius with Cloud Radars  

Science Conference Proceedings (OSTI)

In situ samples of cloud droplets by aircraft in Oklahoma in 1997, the Surface Heat Budget of the Arctic Ocean (SHEBA)/First ISCCP Regional Experiment (FIRE)-Arctic Cloud Experiment (ACE) in 1998, and various other locations around the world were ...

Shelby Frisch; Matthew Shupe; Irina Djalalova; Graham Feingold; Michael Poellot

2002-06-01T23:59:59.000Z

44

Simulating mixed-phase Arctic stratus clouds: sensitivity to ice initiation mechanisms  

E-Print Network (OSTI)

M. : Role of a parameterized ice-phase mi- crophysics in anof contact nucleation in ice phase initiation in clouds, J.simulated, process of ice phase initiation due to freezing

Sednev, I.

2008-01-01T23:59:59.000Z

45

Simulating mixed-phase Arctic stratus clouds: Sensitivity to ice initiation mechanisms  

E-Print Network (OSTI)

M. : Role of a parameterized ice-phase micro- physics in anconcentration (N i ) for ice phase in experiments with icei L ?1 Table 8. Composite ice phase effective radius (R ei )

Sednev, I.

2009-01-01T23:59:59.000Z

46

Simulating mixed-phase Arctic stratus clouds: Sensitivity to ice initiationmechanisms  

SciTech Connect

The importance of Arctic mixed-phase clouds on radiation and the Arctic climate is well known. However, the development of mixed-phase cloud parameterization for use in large scale models is limited by lack of both related observations and numerical studies using multidimensional models with advanced microphysics that provide the basis for understanding the relative importance of different microphysical processes that take place in mixed-phase clouds. To improve the representation of mixed-phase cloud processes in the GISS GCM we use the GISS single-column model coupled to a bin resolved microphysics (BRM) scheme that was specially designed to simulate mixed-phase clouds and aerosol-cloud interactions. Using this model with the microphysical measurements obtained from the DOE ARM Mixed-Phase Arctic Cloud Experiment (MPACE) campaign in October 2004 at the North Slope of Alaska, we investigate the effect of ice initiation processes and Bergeron-Findeisen process (BFP) on glaciation time and longevity of single-layer stratiform mixed-phase clouds. We focus on observations taken during October 9th-10th, which indicated the presence of a single-layer mixed-phase clouds. We performed several sets of 12-hour simulations to examine model sensitivity to different ice initiation mechanisms and evaluate model output (hydrometeors concentrations, contents, effective radii, precipitation fluxes, and radar reflectivity) against measurements from the MPACE Intensive Observing Period. Overall, the model qualitatively simulates ice crystal concentration and hydrometeors content, but it fails to predict quantitatively the effective radii of ice particles and their vertical profiles. In particular, the ice effective radii are overestimated by at least 50%. However, using the same definition as used for observations, the effective radii simulated and that observed were more comparable. We find that for the single-layer stratiform mixed-phase clouds simulated, process of ice phase initiation due to freezing of supercooled water in both saturated and subsaturated (w.r.t. water) environments is as important as primary ice crystal origination from water vapor. We also find that the BFP is a process mainly responsible for the rates of glaciation of simulated clouds. These glaciation rates cannot be adequately represented by a water-ice saturation adjustment scheme that only depends on temperature and liquid and solid hydrometeors contents as is widely used in bulk microphysics schemes and are better represented by processes that also account for supersaturation changes as the hydrometeors grow.

Sednev, I.; Menon, S.; McFarquhar, G.

2009-04-10T23:59:59.000Z

47

Simulating mixed-phase Arctic stratus clouds: sensitivity to ice initiation mechanisms  

SciTech Connect

The importance of Arctic mixed-phase clouds on radiation and the Arctic climate is well known. However, the development of mixed-phase cloud parameterization for use in large scale models is limited by lack of both related observations and numerical studies using multidimensional models with advanced microphysics that provide the basis for understanding the relative importance of different microphysical processes that take place in mixed-phase clouds. To improve the representation of mixed-phase cloud processes in the GISS GCM we use the GISS single-column model coupled to a bin resolved microphysics (BRM) scheme that was specially designed to simulate mixed-phase clouds and aerosol-cloud interactions. Using this model with the microphysical measurements obtained from the DOE ARM Mixed-Phase Arctic Cloud Experiment (MPACE) campaign in October 2004 at the North Slope of Alaska, we investigate the effect of ice initiation processes and Bergeron-Findeisen process (BFP) on glaciation time and longevity of single-layer stratiform mixed-phase clouds. We focus on observations taken during 9th-10th October, which indicated the presence of a single-layer mixed-phase clouds. We performed several sets of 12-h simulations to examine model sensitivity to different ice initiation mechanisms and evaluate model output (hydrometeors concentrations, contents, effective radii, precipitation fluxes, and radar reflectivity) against measurements from the MPACE Intensive Observing Period. Overall, the model qualitatively simulates ice crystal concentration and hydrometeors content, but it fails to predict quantitatively the effective radii of ice particles and their vertical profiles. In particular, the ice effective radii are overestimated by at least 50%. However, using the same definition as used for observations, the effective radii simulated and that observed were more comparable. We find that for the single-layer stratiform mixed-phase clouds simulated, process of ice phase initiation due to freezing of supercooled water in both saturated and undersaturated (w.r.t. water) environments is as important as primary ice crystal origination from water vapor. We also find that the BFP is a process mainly responsible for the rates of glaciation of simulated clouds. These glaciation rates cannot be adequately represented by a water-ice saturation adjustment scheme that only depends on temperature and liquid and solid hydrometeors contents as is widely used in bulk microphysics schemes and are better represented by processes that also account for supersaturation changes as the hydrometeors grow.

Sednev, Igor; Sednev, I.; Menon, S.; McFarquhar, G.

2008-02-18T23:59:59.000Z

48

Simulating mixed-phase Arctic stratus clouds: Sensitivity to ice initiation mechanisms  

E-Print Network (OSTI)

parameterization in BRM scheme accounts for two general mech- anisms distinguishable according to the involvement of liquid phase in the ice

Sednev, I.

2009-01-01T23:59:59.000Z

49

Evaluation of COAMPS Forecasts of Coastal Stratus Using Satellite Microphysical Retrievals and Aircraft Measurements  

Science Conference Proceedings (OSTI)

A field project was carried out offshore of central Oregon during August 1999 to evaluate mesoscale model simulations of coastal stratiform cloud layers. Procedures for mapping cloud physical parameters such as cloud optical depth, droplet ...

Melanie A. Wetzel; Steven K. Chai; Marcin J. Szumowski; William T. Thompson; Tracy Haack; Gabor Vali; Robert Kelly

2001-10-01T23:59:59.000Z

50

The Shipboard Use of a Low-Level Atmospheric Thermograph in Fog and Stratus Investigations  

Science Conference Proceedings (OSTI)

A Low-Level Atmospheric Thermograph (LLAT) to obtain fine-scaled and detailed vertical temperature profiles to an altitude of 1000 m has been developed through a simple modification of the Sippican Expendable Bathythermograph (XBT) system. Only ...

J. G. Norton; G. E. Schacher

1980-02-01T23:59:59.000Z

51

Doppler Cloud Radar Derived Drop Size Distributions in Liquid Water Stratus Clouds  

Science Conference Proceedings (OSTI)

A cloud particle size retrieval algorithm that uses radar reflectivity factor and Doppler velocity obtained by a 35-GHz Doppler radar and liquid water path estimated from microwave radiometer radiance measurements is developed to infer the size ...

Seiji Kato; Gerald G. Mace; Eugene E. Clothiaux; James C. Liljegren; Richard T. Austin

2001-10-01T23:59:59.000Z

52

Effects of Aerosol and Horizontal Inhomogeneity on the Broadband Albedo of Marine Stratus: Numerical Simulations  

Science Conference Proceedings (OSTI)

Recent estimates of the effect of increasing amounts of anthropogenic sulfate aerosol on the radiative forcing of the atmosphere have indicated that its impact may be comparable in magnitude to the effect from increases in CO2. Much of this ...

D. P. Duda; G. L. Stephens; B. Stevens; W. R. Cotton

1996-12-01T23:59:59.000Z

53

Transition of Stratus into Fog along the California Coast: Observations and Modeling  

Science Conference Proceedings (OSTI)

A case of fog formation along the California coast is examined with the aid of a one-dimensional, higher-order, turbulence-closure model in conjunction with a set of myriad observations. The event is characterized by persistent along-coast winds ...

Darko Kora?in; John Lewis; William T. Thompson; Clive E. Dorman; Joost A. Businger

2001-07-01T23:59:59.000Z

54

Numerical Simulations of Observed Arctic Stratus Clouds Using a Second-Order Turbulence Closure Model  

Science Conference Proceedings (OSTI)

A high-resolution one-dimensional version of a second-order turbulence closure radiative-convective model, developed at Los Alamos National Laboratory, is used to simulate the interactions among turbulence, radiation, and bulk cloud parameters in ...

W. S. Smith; C-Y. J. Kao

1996-01-01T23:59:59.000Z

55

Coincident In Situ and W-Band Radar Measurements of Drop Size Distribution in a Marine Stratus Cloud and Drizzle  

Science Conference Proceedings (OSTI)

Investigation of precipitation formation requires measurements of the drop size distribution in a cloud. These measurements have usually been made using ground-based radar systems or aircraft in situ probes. Difficulties encountered in practice ...

J. Galloway; A. Pazmany; J. Mead; R. E. McIntosh; D. Leon; J. French; S. Haimov; R. Kelly; G. Vali

1999-05-01T23:59:59.000Z

56

AltoStratus: A Collaboration Network Focused on the New Research Challenges and Opportunities in Cloud Computing  

Science Conference Proceedings (OSTI)

Cloud Computing is a new computing paradigm with the potential to radically change the way Internet applications and services are specified, developed, deployed, executed, managed, operated and evolved. Among the several benefits commonly associated ... Keywords: cloud computing, collaboration network, research challenges

Thais Batista; Nabor Mendonca; Americo Sampaio; Carlos Alberto Kamienski; Nelson Fonseca; Edmundo Madeira; Luciano Gaspary; Marinho Barcellos; Noemi Rodriguez; Karin Breitman; Djamel Sadok; Silvio Meira; Stenio Fernandes; Flvia C. Delicato; Paulo F. Pires

2011-09-01T23:59:59.000Z

57

Atmospheric Radiation Measurement (ARM) Data from Point Reyes, California for the Marine Stratus, Radiation, Aerosol, and Drizzle (MASRAD) Project  

DOE Data Explorer (OSTI)

The Office of Biological and Environmental Research in DOE's Office of Science is responsible for the ARM Program. The ARM Archive physically resides at the Oak Ridge National Laboratory.

58

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 MayOctober 2006 over southern tropical West Africa are investigated using cloudiness ...

Jon M. Schrage; Andreas H. Fink

2012-06-01T23:59:59.000Z

59

The dependence of ice microphysics on aerosol concentration in arctic mixed-phase stratus clouds during ISDAC and M-PACE  

SciTech Connect

Cloud and aerosol data acquired by the National Research Council of Canada (NRC) Convair-580 aircraft in, above, and below single-layer arctic stratocumulus cloud during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) in April 2008 were used to test three aerosol indirect effects hypothesized to act in mixed-phase clouds: the riming indirect effect, the glaciation indirect effect, and the cold second indirect effect. The data showed a correlation of R= 0.75 between liquid drop number concentration, Nliq, inside cloud and ambient aerosol number concentration NPCASP below cloud. This, combined with increasing liquid water content LWC with height above cloud base and the nearly constant profile of Nliq, suggested that liquid drops were nucleated from aerosol at cloud base. No strong evidence of a riming indirect effect was observed, but a strong correlation of R = 0.69 between ice crystal number concentration Ni and NPCASP above cloud was noted. Increases in ice nuclei (IN) concentration with NPCASP above cloud combined with the subadiabatic LWC profiles suggest possible mixing of IN from cloud top consistent with the glaciation indirect effect. The higher Nice and lower effective radius rel for the more polluted ISDAC cases compared to data collected in cleaner single-layer stratocumulus conditions during the Mixed-Phase Arctic Cloud Experiment is consistent with the operation of the cold second indirect effect. However, more data in a wider variety of meteorological and surface conditions, with greater variations in aerosol forcing, are required to identify the dominant aerosol forcing mechanisms in mixed-phase arctic clouds.

Jackson, Robert C.; McFarquhar, Greg; Korolev, Alexei; Earle, Michael; Liu, Peter S.; Lawson, R. P.; Brooks, Sarah D.; Wolde, Mengistu; Laskin, Alexander; Freer, Matthew

2012-08-14T23:59:59.000Z

60

FEG2001_inside front cover.p65  

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

16 Stratus 10 Stratus 4-DR 12 Viper Conv 8 Viper Coupe 8 F FERRARI 360 ModenaSpider 8 456 MGTMGTA 9 550 MaranelloBarchetta 8 FORD Crown Victoria 13 Crown Victoria (nat'l gas)...

Note: This page contains sample records for the topic "mase-marine stratus experiment-pt" 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

Receiving Water Uses, Impairments, and Sources of Stormwater Pollutants  

E-Print Network (OSTI)

that the confirmation test be conducted with Stratus Petroleum sediment on site. Using the Stratus sediment on-week confirmation test with about 100 tons of Stratus Petroleum sediment is $367,200. iv #12;Following and blending the Ecomelt with Portland cement or another lime source ­ can be accomplished at an off

Pitt, Robert E.

62

ARM - Publications: Science Team Meeting Documents  

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

Radiometer Measurements and Retrievals Using Time Series Analyses* Effect of Stratus on Solar Radiation: A Study using Millimeter Wave Cloud Radar and Microwave Radiometer Data...

63

1  

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

Tenth ARM Science Team Meeting Proceedings, San Antonio, Texas, March 13-17, 2000 1 Objective Synoptic Classification of Stratus: Impact on Macroscopic Cloud Statistics J. C....

64

ARM - Publications: Science Team Meeting Documents  

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

in Stratus Clouds Evidence of High Ice Supersaturation in Cirrus Clouds Using ARM Raman Lidar Measurements* Local Correlations and Multifractal Behavior in Marine Boundary Layer...

65

8, 1175511819, 2008 mixed-phase Arctic  

E-Print Network (OSTI)

, process of ice phase initiation due to freezing of25 supercooled water in both saturatedACPD 8, 11755­11819, 2008 Simulating mixed-phase Arctic stratus clouds I. Sednev et al. Title Page.0 License. Atmospheric Chemistry and Physics Discussions Simulating mixed-phase Arctic stratus clouds

Paris-Sud XI, Université de

66

Microsoft PowerPoint - poster for ARM 2007 5  

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

process in single-layer arctic stratus during MPACE process in single-layer arctic stratus during MPACE Gong Zhang 1 , Greg McFarquhar 1 , Johannes Verlinde 2 , Michael Poellot 3 , Greg Kok 4 , Edwin Eloranta 5 , Paul DeMott 6 , Tony Prenni 6 and Andrew Heymsfield 7 1 University of Illinois 2 Pennsylvania State University 3 University of North Dakota 4 Droplet Measurement Technologies 5 University of Wisconsin 6 Colorado State University 7 National Center for Atmospheric Research 1 Arctic boundary single-layer stratus 2 Vertical cloud structure 5. Acknowledgments This research was supported by DOE ARM under contract number DE-FG02-00ER62913. FIG 1 Backscatter intensity and depolarization ratio measured by Wisconsin HSRL Lidar in Barrow, AK. During MPACE, single- layer arctic stratus was observed from Oct 09 2004 to Oct 12 2004.

67

Austin(2)-RT  

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

Stratus Sensing in the CloudSat Antecedent Stratus Sensing in the CloudSat Antecedent Validation Experiment (CAVEX99) R. T. Austin, G. L. Stephens, R. F. McCoy, Jr., R. B. McCoy, and S. D. Miller Department of Atmospheric Science Colorado State University Fort Collins, Colorado S. M. Sekelsky Microwave Remote Sensing Laboratory University of Massachusetts Amherst, Massachusetts Introduction The CloudSat Antecedent Validation Experiment (CAVEX99) was one component of the Monterey Coastal Stratus Experiment (MCSE), a multi-experiment study of maritime stratus conducted off the Pacific coast near Monterey, California, in June and July 1999. MCSE was proposed and organized by Professor Bruce Albrecht of the University of Miami and Professor Qing Wang of the Naval Postgraduate School; it was supported by the Office of Naval Research. CAVEX was proposed as an

68

ARM - Facility News Article  

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

December 3, 2004 [Facility News] December 3, 2004 [Facility News] First Deployment of ARM Mobile Facility to Occur on California Coast Bookmark and Share Image - Point Reyes Beach Image - Point Reyes Beach Point Reyes National Seashore, on the California coast north of San Francisco, has been identified as the official location for the first deployment of the DOE's Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF). As part of a 6-month field campaign beginning in March 2005 to study the microphysical characteristics of marine stratus and, in particular, marine stratus drizzle processes, the AMF will provide a mature instrument system to help fill information gaps in the existing limited surveys of marine stratus microphysical structure. Marine stratus clouds are known to be susceptible to the byproducts of fossil fuel consumption, a

69

ARM - Publications: Science Team Meeting Documents  

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

Stratus Microphysical Parameters Using Radar and Visible Stratus Microphysical Parameters Using Radar and Visible Optical Depth Austin, R.T. and Stephens, G.L., Colorado State University, Fort Collins Eleventh Atmospheric Radiation Measurement (ARM) Science Team Meeting A new algorithm for the retrieval of stratus cloud microphysical parameters was introduced last year and applied to measurements of maritime stratus clouds off the coast of California. The retrieval has been refined and applied to data from the Southern Great Plains CART site, as well as to the original California marine measurements. The poster will describe these refined results, discuss error analysis of the algorithm, show how the retrieval compares with analogous radar-only retrievals, and discuss other products and benefits of the algorithm's estimation theory formulation

70

Cloud Droplet Size Distributions in Low-Level Stratiform Clouds  

Science Conference Proceedings (OSTI)

A database of stratus cloud droplet (diameter <50 ?m) size distribution parameters, derived from in situ data reported in the existing literature, was created, facilitating intercomparison among datasets and quantifying typical values and their ...

Natasha L. Miles; Johannes Verlinde; Eugene E. Clothiaux

2000-01-01T23:59:59.000Z

71

Role of Low Clouds in Summertime AtmosphereOcean Interactions over the North Pacific  

Science Conference Proceedings (OSTI)

The summer-to-summer variability of the areal extent of marine stratiform cloudiness (MSC; stratus, stratocumulus, and fog) over the North Pacific is examined for the period of record 195292 using a dataset based on surface observations. ...

Joel R. Norris; Yuan Zhang; John M. Wallace

1998-10-01T23:59:59.000Z

72

A Report of the National Assessment  

E-Print Network (OSTI)

) Precipitation Evaporation Ocean Model Layers Stratus Clouds Transition from Solid to Vapor Outgoing Heat Energy Snow Cover Runoff Evaporative and Heat Energy Exchanges Incoming Solar Energy Atmosphere Cumulus Clouds Cirrus Clouds Sea Ice Vertical Overturning Precipitation & Evaporation Heat & Salinity Exchange

McCarl, Bruce A.

73

Modeling Entrainment and Finescale Mixing in Cumulus Clouds  

Science Conference Proceedings (OSTI)

A model used to study entrainment and mixing of thermodynamic properties in the stratus-topped boundary layer has been extended to represent these processes in cumulus clouds. The new model, called the explicit mixing parcel model (EMPM), ...

Steven K. Krueger; Chwen-Wei Su; Patrick A. McMurtry

1997-12-01T23:59:59.000Z

74

1  

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

Tenth ARM Science Team Meeting Proceedings, San Antonio, Texas, March 13-17, 2000 1 Breakup of Stratus Cloud Structure Predicted from Non-Brownian Motion Liquid Water Fluctuations...

75

Numerical Investigations of the Roles of Radiative and Evaporative Feedbacks in Stratocumulus Entrainment and Breakup  

Science Conference Proceedings (OSTI)

When the surface buoyancy flux is small and the shear is weak, turbulence circulations within a stratus-topped boundary layer are driven by two buoyancy-generating processes at cloud top: radiative cooling and evaporative cooling. These two ...

Chin-Hoh Moeng; Don H. Lenschow; David A. Randall

1995-08-01T23:59:59.000Z

76

ARM - Publications: Science Team Meeting Documents  

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

Relative Importance of Size Distribution and Liquid Water Path to Solar Radiation in the Presence of Continental Stratus Sengupta, M.(a), Ackerman, T.P.(a), and Clothiaux, E.E.(b),...

77

Importance of Accurate Liquid Water Path for Estimation of Solar Radiation in Warm Boundary Layer Clouds: An Observational Study  

Science Conference Proceedings (OSTI)

A 1-yr observational study of overcast boundary layer stratus at the U.S. Department of Energy Atmospheric Radiation Measurement Program Southern Great Plains site illustrates that surface radiation has a higher sensitivity to cloud liquid water ...

Manajit Sengupta; Eugene E. Clothiaux; Thomas P. Ackerman; Seiji Kato; Qilong Min

2003-09-01T23:59:59.000Z

78

Detection of Cloud-Top Height from Backscattered Radiances within the Oxygen A Band. Part 2: Measurements  

Science Conference Proceedings (OSTI)

Cloud-top heights were successfully derived from reflected solar radiation measurements within the oxygen A-band absorption. The accuracy of the estimated cloud-top heights was to within 40 meters over stratus clouds when compared with ...

J. Fischer; W. Cordes; A. Schmitz-Peiffer; W. Renger; P. Mrl

1991-09-01T23:59:59.000Z

79

Further Observations of the Production of Ice Particles in Clouds by Aircraft  

Science Conference Proceedings (OSTI)

Evidence is presented for the production of high concentrations of rather uniformly-sized ice crystals in a supercooled stratus cloud by a commercial, turbine, propeller-driven aircraft.

Arthur L. Rangno; Peter V. Hobbs

1984-06-01T23:59:59.000Z

80

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

Note: This page contains sample records for the topic "mase-marine stratus experiment-pt" 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

Drizzle Suppression in Ship Tracks  

Science Conference Proceedings (OSTI)

Although drizzle was a relatively infrequent occurrence during the Monterey Area Ship Track study, diverse measurements from several sources produced data signals consistent with a reduction in drizzle drops in stratus clouds affected by ship ...

Ronald J. Ferek; Timothy Garrett; Peter V. Hobbs; Scott Strader; Doug Johnson; Jonathan P. Taylor; Kurt Nielsen; Andrew S. Ackerman; Yefim Kogan; Qingfu Liu; Bruce A. Albrecht; David Babb

2000-08-01T23:59:59.000Z

82

The Impact of Ship-Produced Aerosols on the Microstructure and Albedo of Warm Marine Stratocumulus Clouds: A Test of MAST Hypotheses 1i and 1ii  

Science Conference Proceedings (OSTI)

Anomalously high reflectivity tracks in stratus and stratocumulus sheets associated with ships (known as ship tracks) are commonly seen in visible and near-infrared satellite imagery. Until now there have been only a limited number of in situ ...

P. A. Durkee; K. J. Noone; R. J. Ferek; D. W. Johnson; J. P. Taylor; T. J. Garrett; P. V. Hobbs; J. G. Hudson; C. S. Bretherton; G. Innis; G. M. Frick; W. A. Hoppel; C. D. ODowd; L. M. Russell; R. Gasparovic; K. E. Nielsen; S. A. Tessmer; E. strm; S. R. Osborne; R. C. Flagan; J. H. Seinfeld; H. Rand

2000-08-01T23:59:59.000Z

83

Parameterization of Radiative Flux Profiles within Layer Clouds  

Science Conference Proceedings (OSTI)

The vertical structure of radiative flux profiles within clouds can have a significant impact on the thermodynamic processes that maintain and dissipate the clouds, particularly in the case of marine stratus and stratocumulus. However, dynamic ...

Howard P. Hanson; Vernon E. Derr

1987-11-01T23:59:59.000Z

84

A Model to Determine Open or Closed Cellular Convection  

Science Conference Proceedings (OSTI)

A simple mechanism is proposed to help explain the observed presence in the atmosphere of open or closed cellular convection. If convection is produced by cooling concentrated near the top of the cloud layer, as in radiative cooling of stratus ...

H. Mark Helfand; Eugenia Kalnay

1983-03-01T23:59:59.000Z

85

Seasonal Simulations of the Planetary Boundary Layer and Boundary-Layer Stratocumulus Clouds with a General Circulation Model  

Science Conference Proceedings (OSTI)

The UCLA general circulation model (GCM) has been used to simulate the seasonally varying planetary boundary layer (PBL), as well as boundary-layer stratus and stratocumulus clouds. The PBL depth is a prognostic variable of the GCM, incorporated ...

David A. Randall; James A. Abeles; Thomas G. Corsetti

1985-04-01T23:59:59.000Z

86

A Climatology of Midlatitude Continental Clouds from the ARM SGP Central Facility: Part I: Low-Level Cloud Macrophysical, Microphysical, and Radiative Properties  

Science Conference Proceedings (OSTI)

A record of single-layer and overcast low cloud (stratus) properties has been generated using approximately 4000 h of data collected from January 1997 to December 2002 at the Atmospheric Radiation Measurement (ARM) Southern Great Plains Central ...

Xiquan Dong; Patrick Minnis; Baike Xi

2005-05-01T23:59:59.000Z

87

ARM - Publications: Science Team Meeting Documents  

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

and in Low Sun Conditions* Heck, P.W., Rapp, A.D., Minnis, P., Smith, Jr., W.L., and Nguyen, L. An Integrated Algorithm for Retrieving Low-Level Stratus Cloud Microphysical...

88

Observational Evidence That Enhanced Subsidence Reduces Subtropical Marine Boundary Layer Cloudiness  

Science Conference Proceedings (OSTI)

Conventional wisdom suggests that subsidence favors the presence of marine stratus and stratocumulus because regions of enhanced boundary layer cloudiness are observed to climatologically co-occur with regions of enhanced subsidence. Here it is ...

Timothy A. Myers; Joel R. Norris

2013-10-01T23:59:59.000Z

89

Cloud Top Liquid Water from Lidar Observations of Marine Stratocumulus  

Science Conference Proceedings (OSTI)

Maine stratus clouds were simultaneously observed by nadir Nd:YAG lidar measurements and in situ cloud physics measurements. A procedure was applied to derive the two-dimensional vertical cross section of the liquid water from within the cloud ...

J. D. Spinhirne; R. Boers; W. D. Hart

1989-02-01T23:59:59.000Z

90

ARM - Campaign Instrument - rwp  

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

Carbonaceous Aerosol and Radiative Effects Study (CARES) Download Data McClellan AFB, Sacramento, CA, 2010.06.02 - 2010.06.28 MASRAD: Pt. Reyes Stratus Cloud and Drizzle Study...

91

gottschalck(1)-99  

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

Macroscopic Cloud and Boundary Layer Properties for Macroscopic Cloud and Boundary Layer Properties for Continental Stratus at the SGP CART Site During 1997 J. C. Gottschalck and B. A. Albrecht University of Miami Miami, Florida Introduction Stratus and stratocumulus clouds are important in the regulation of the earth's radiation budget and thus play an important role in climate over both the land and ocean (Ramanathan et al. 1989). Consequently, there is a great need for accurate boundary layer cloud parameterizations in climate models (Slingo 1990). Therefore, it is necessary that adequate observational data bases exist for both continental and maritime boundary layer clouds. Currently our observational and modeling understanding for marine stratus is much more advanced than that for continental clouds (Albrecht et al. 1988; Albrecht et al.

92

Charge  

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

ARM-0501 ARM-0501 Marine Stratus Radiation, Aerosol, and Drizzle (MASRAD) Science Plan June 2005 M.A. Miller Brookhaven National Laboratory Earth System Science Division Upton, New York A. Bucholtz Naval Research Laboratory Monterey, California B. Albrecht and P. Kollias Rosenstiel School of Marine and Atmospheric Science Miami, Florida Work supported by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research M.A. Miller et al., June 2005, DOE/ER-ARM-0501 Abstract Marine stratus is one of the most prevalent and under sampled cloud types on earth and is an important component of the earth's climate system. Marine stratus is thought to be susceptible to infusions of anthropogenic aerosols that alter in-cloud microphysical processes and is known to

93

frisch-98.pdf  

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

9 9 On Stratus Cloud Liquid Water Profiles from a Cloud Radar and Microwave Radiometer A. S. Frisch and G. Feingold Cooperative Institute for Research in the Atmosphere Colorado State University and NOAA-Environmental Technology Laboratory Boulder, Colorado C. W. Fairall NOAA-Environmental Technology Laboratory Boulder, Colorado J. B. Snider Cooperative Institute for Research in the Atmosphere Colorado State University Boulder, Colorado Introduction Stratus clouds are important in boundary-layer dynamics and global climate. Most measurements of stratus clouds have been made with aircraft (Slingo et al. 1982a, Slingo et al. 1982b, Nicholls 1987). However, aircraft measure- ments are expensive, and cannot be used for long-term monitoring at a single location. The development of the

94

dong-99.PDF  

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

25-Month Data Base of Stratus Cloud Properties 25-Month Data Base of Stratus Cloud Properties Generated from Ground-Based Measurements at the ARM SGP Site X. Dong Analytical Services and Materials, Inc. Hampton, Virginia P. Minnis Atmospheric Sciences Division National Aeronautics and Space Administration Langley Research Center Hampton, Virginia T. P. Ackerman, E. E. Clothiaux, and C. N. Long Department of Meteorology Pennsylvania State University University Park, Pennsylvania G. G. Mace Meteorology Department University of Utah Salt Lake City, Utah J. C. Liljegren Ames Laboratory Ames, Iowa Introduction Boundary layer stratiform clouds are important in the regulation of the earth's radiation budget and play an important role in climate over both land and ocean (Ramanathan et al. 1989). Boundary layer stratus

95

PowerPoint Presentation  

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

Aerosol Indirect Effects in California Coastal Stratus and Fog Aerosol Indirect Effects in California Coastal Stratus and Fog SUMMARY Data from the AMF deployment during MASRAD can be used to directly test the performance of existing cloud droplet nucleation parameterizations in coastal stratus clouds. The example below is a test of Twomey's 1959 parameterization. More sophisticated parameterizations have been formulated and will be tested in a similar manner. 3. Air Mass Source Analysis The HYbrid Single-Particle Lagrangian Integrated Trajectory model (HYSPLIT) was used to identify aerosol source areas and paths taken by aerosols reaching the Pt. Reyes site. A 10-day back trajectory was computed for each radiosonde launch at two starting heights: one 25 meters below the lowest inversion and the second 25 meters above.

96

1  

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

Effect of Stratus on Solar Radiation: A Study Using Effect of Stratus on Solar Radiation: A Study Using Millimeter Wave Cloud Radar and Microwave Radiometer Data From the Southern Great Plains M. Sengupta and T. P. Ackerman Pacific Northwest National Laboratory Richland, Washington E. E. Clothiaux The Pennsylvania State University University Park, Pennsylvania Introduction Clouds are important players in the global radiation budget with low-level water clouds being one of the most influential types. Classified as stratocumulus and stratus, these water clouds cover 34% of oceans and 18% of land at any given time (Considine et al. 1997). A 50% plus global coverage, a high albedo when compared to the ocean, and temperatures comparable to the surface causes the low stratiform clouds to provide about 60% of the annually averaged net cloud radiative forcing (Hartmann et al.

97

Primitive Analysis of the Ship Tracking Problem  

Science Conference Proceedings (OSTI)

Satellite images reveal tracks of enhanced solar reflectivity in low-level stratus clouds over the ocean that are known to be produced by the aerosols emitted from diesel-powered ships. The question arises: Can we track a ship from such images? A ...

J. R. Philip; J. W. Rottman

2000-07-01T23:59:59.000Z

98

Short-term variability of overcast brightness Raymond L. Lee, Jr. and Javier Hernndez-Andrs  

E-Print Network (OSTI)

stratus overcast at USNA on 4-21-03 with the E trend predicted by the radiative transfer model MODTRAN4. Despite MODTRAN's complexity and versatility, its verisi- militude is not striking in Fig. 14 for fixed model cloud thickness z. Figure 14's MODTRAN simula- tion parameters include typical seasonal

Lee Jr., Raymond L.

99

Energy Research and Development Division FINAL PROJECT REPORT  

E-Print Network (OSTI)

Energy Research and Development Division FINAL PROJECT REPORT COMPENSATION CEC5002013114 Prepared for: California Energy Commission Prepared by: Stratus Consulting Inc. #12-04-025 Prepared for: California Energy Commission Joe O'Hagan Contract Manager Linda Spiegel Office Manager Energy

100

Deployment of a Tethered-Balloon System for Microphysics and Radiative Measurements in Mixed-Phase Clouds at Ny-lesund and South Pole  

Science Conference Proceedings (OSTI)

A tethered-balloon system capable of making microphysical and radiative measurements in clouds is described and examples of measurements in boundary layer stratus clouds in the Arctic and at the South Pole are presented. A 43-m3 helium-filled ...

R. Paul Lawson; Knut Stamnes; Jakob Stamnes; Pat Zmarzly; Jeff Koskuliks; Chris Roden; Qixu Mo; Michael Carrithers; Geoffrey L. Bland

2011-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "mase-marine stratus experiment-pt" 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

Radiative Processes Working Group  

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

5.3 Stratocumulus (0.12) -13.2 7.3 Stratus (0.02) -2.6 1.2 Cloud Optical Thickness Passive remote sensing : ISCCP Chen et al. 2000 Pressure 0 3.6 23 379 50 440 680 1000...

102

zhang(1)-98.pdf  

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

7 7 The Influence of Radiation and Large-Scale Vertical Motion on the Persistence of Arctic Stratus Clouds Q. Zhang and K. Stamnes Geophysical Institute University of Alaska Fairbanks, Alaska D. K. Lilly Cooperative Institute for Meteorological Satellite Studies University of Oklahoma Boulder, Oklahoma Introduction Arctic Stratus Clouds (ASCs) are important modulators of local climate, and perhaps even global climate. One of the most significant features of ASC is that they can persist for several days. Nevertheless, the mechanism responsible for their persistence still remains unknown. Several studies have been undertaken to understand the mechanism of the maintenance of the multiple cloud layers. With a one- dimensional (1-D) second-order turbulence closure model,

103

liesvend-98.pdf  

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

A Simple, Yet Realistic Model for the Formation of Arctic A Simple, Yet Realistic Model for the Formation of Arctic Stratus Clouds-A Case Study O. Lie-Svendsen Norwegian Defense Research Establishment Kjeller, Norway Q. Zhang, J. Simmons, and K. Stamnes Geophysical Institute University of Alaska, Fairbanks Introduction We have developed a one-dimensional radiative-convective model with detailed cloud microphysics, and used it to study the formation of Arctic Stratus clouds (ASC). The model contains detailed radiative and microphysical modules, and it provides a self-consistent treatment of the interaction between radiative and cloud microphysical processes important for cloud formation. The radiative transfer code is coupled to the microphysics module that has been devel- oped to simulate the detailed cloud droplet activation and

104

ARM - Facility News Article  

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

Mobile Facility Beta Testing Complete; System Headed to California Seashore Mobile Facility Beta Testing Complete; System Headed to California Seashore Bookmark and Share A key addition to the ARM Climate Research Facility scientific infrastructure is ready to roll...literally. In February, the ARM Mobile Facility (AMF) is being packed up and shipped from Richland, Washington, to the Point Reyes National Seashore north of San Francisco, California. There, it will be reassembled in preparation for its first deployment as part of a 6-month experiment to study the microphysical characteristics of marine stratus clouds, and in particular, marine stratus drizzle processes. Throughout the deployment, the AMF will accommodate aerosol observing equipment for National Oceanic and Atmospheric Administration (NOAA) researchers co-sponsored by ARM and the DOE Aerosol Science Program.

105

PowerPoint Presentation  

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

Coupling Between Oceanic Upwelling and Cloud Coupling Between Oceanic Upwelling and Cloud Coupling Between Oceanic Upwelling and Cloud - - Aerosol Properties Aerosol Properties at the AMF Point Reyes Site at the AMF Point Reyes Site Maureen Dunn , Mike Jensen , Pavlos Kollias , Mark Miller , Peter Daum Mary Jane Bartholomew , David Turner , Elisabeth Andrews and Anne Jefferson Introduction Ground based observations from the MASRAD, Pt. Reyes AMF July 1-Sept 15, 2005 indicate a relationship between coastal marine stratus cloud properties, boundary layer cloud condensation nuclei and the upwelling of cool oceanic waters measured at an offshore NOAA buoy. Cloud Drizzle to CCN Atmosphere to Cloud Upwelling SST to Atmosphere Conclusion Coastal marine stratus clouds increase in thickness as the underlying sea surface

106

X:\ARM_19~1\P225-243.WPD  

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

5 5 Development and Testing of an Aerosol-Stratus Cloud Parameterization Scheme for Middle and High Latitudes P. Q. Olsson, M. P. Meyers, S. Kreidenweis, and W. R. Cotton Department of Atmospheric Science Colorado State University Fort Collins, Colorado Introduction The aim of this new project is to develop an aerosol/cloud microphysics parameterization of mixed-phase stratus and boundary layer clouds. Our approach is to create, test, and implement a bulk-microphysics/aerosol model using data from Atmospheric Radiation Measurement (ARM) Cloud and Radiation Testbed (CART) sites and large-eddy simulation (LES) explicit bin-resolving aerosol/micro- physics models. The primary objectives of this work are twofold. First, we need the prediction of number con- centrations of activated aerosol which are transferred to the

107

Microsoft PowerPoint - ARMST2007_mp.ppt  

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

Motions in Arctic Mixed-Phase Stratus Motions in Arctic Mixed-Phase Stratus Matthew D. Shupe a , Pavlos Kollias b , Ola Persson a , Ed Luke b Greg McFarquhar c , Michael Poellot d , Edwin Eloranta e a CIRES - University of Colorado and NOAA/ESRL/PSD, b Brookhaven National Laboratory, c University of Illinois, d University of North Dakota, e University of Wisonsin Mixed-Phase Cloud Properties Air Motions from Doppler Spectra Funded by: ARM Grant DE-FG02-05ER63965 Summary A Conceptual Model relating air motions and microphysics A Doppler Spectrum Small liquid droplets trace vertical air motions Liquid Droplets Ice Particles Correction for spectral broadening W Aircraft comparisons during M-PACE Vertical velocity (W) and turbulent dissipation rates (ε). Retrieval data are mean (symbol) and middle 90% of data (line)

108

ARM - Publications: Science Team Meeting Documents  

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The Radiative Properties of Uniform and Broken Stratus: An Observational The Radiative Properties of Uniform and Broken Stratus: An Observational and Modelling Study Utilizing the Independent Column Approximation for Solar Radiative Transfer Clothiaux, E.E., The Pennsylvania State University; Barker, H.W., Atmospheric Environment Service of Canada; Kato, S., Hampton University; Dong, X., Analytical Service and Materials, Inc. Ackerman, T.P., The Pennsylvania State University; Liljegren, J.C., Ames Laboratory Ninth Atmospheric Radiation Measurement (ARM) Science Team Meeting The Millimeter-Wave Cloud Radar (MMCR) has operated continuously at the Atmospheric Radiation Measurement (ARM) Program's Southern Great Plains (SGP) site since November 11, 1996. As yet, much of the early data has not been calibrated correctly and insect contamination in the boundary layer is

109

zhang(2)-98.pdf  

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3 3 Formation of Arctic Stratus Clouds: Comparison of Model Predictions with Observed Cloud Structure Q. Zhang and K. Stamnes Geophysical Institute University of Alaska Fairbanks, Alaska O. Lie-Svendsen Norwegian Defense Research Establishment Kjeller, Norway Introduction The importance of the Arctic region to global climate has been highlighted by the climate modeling results in recent years (e.g., Manabe et al. 1991). Arctic stratus clouds (ASC) are not only one of the most significant regional climate features in the Arctic region, but also have an important influence on global climate. They play an impor- tant role in the vertical transfer of heat, moisture and momen- tum in the Arctic boundary layer. Due to lack of observation, the mechanism for the formation

110

Radiative Influences on Glaciation Time-Scales of Mixed-Phase Clouds  

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Radiative Influences on Glaciation Time-Scales of Mixed-Phase Clouds Radiative Influences on Glaciation Time-Scales of Mixed-Phase Clouds Harrington, Jerry The Pennsylvania State University Category: Modeling Mixed-phase stratus clouds are dominant in the Arctic during much of the year. These clouds typically have liquid tops that precipitate ice. Time scales for the complete glaciation of such clouds (the Bergeron process) are typically computed using the classical mass growth equations for crystals and liquid drops. However, mixed phase arctic stratus have significant infrared cooling and solar heating (during the warm season) rates that can affect the growth of water drops and ice crystals, and therefore the strength of the Bergeron process. To examine the influence of radiative heating and cooling on the Bergeron process, we incorporate a

111

The influence of ice nucleation mode and ice vapor growth on simulation of  

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

The influence of ice nucleation mode and ice vapor growth on simulation of The influence of ice nucleation mode and ice vapor growth on simulation of arctic mixed-phase clouds Avramov, Alexander The Pennsylvania State University Category: Modeling Mixed-phase arctic stratus clouds are the predominant cloud type in the Arctic . Perhaps one of the most intriguing of their features is that they tend to have liquid tops that precipitate ice. Despite the fact that this situation is colloidally unstable, these cloud systems are quite long lived - from a few days to over a couple of weeks. Previous studies have suggested that this longevity may be due to a paucity of ice nucleating aerosols (ice nuclei, or IN) in the Arctic. Such studies have shown that small changes in IN concentrations can cause large changes in the amount of liquid water within a mixed-phase stratus deck. We use the Regional

112

kollias-98.pdf  

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7 7 High Resolution Doppler Radar Observations in Continental Stratus Clouds P. Kollias and B. A. Albrecht University of Miami Miami, Florida Introduction Vertical mixing is a key factor in determining the macroscopic and microscopic structure of stratus clouds. The vertical velocities resolved from millimeter-wavelength radars can be used to define the turbulence structure within such clouds (Frisch et al. 1995). To illustrate the utility of such radar measurements for studying the turbulence structure of continental stratocumulus clouds, eight continuous hours of 2-second observations from the Doppler Pennsylvania State University (PSU) 94-GHz radar are analyzed. These observations are used to study the temporal evolution of the turbulence structure of the cloud

113

Section 77  

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Figure 1. Potential temperature, equivalent Figure 1. Potential temperature, equivalent potential temperature, and saturation equiva- lent potential temperature for a) the decou- pled boundary-layer observed over the ARM SGP site and b) the well-mixed boundary- layer observed over central Pennsylvania. Observational Studies of Continental Stratus-Implications for Modeling B. A. Albrecht University of Miami Miami, Florida G. G. Mace University of Utah Salt Lake City, Utah H. Verlinde and T. P. Ackerman Pennsylvania State University University Park, Pennsylvania Introduction Data from the Atmospheric Radiation Measurement (ARM) Program Southern Great Plains (SGP) site have tremendous potential for providing statistical descriptions of cloud and boundary layer properties associated with continental stratus.

114

ARM - Publications: Science Team Meeting Documents  

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Comparison of Stratus Cloud Optical Depths Retrieved from Surface and GOES Comparison of Stratus Cloud Optical Depths Retrieved from Surface and GOES Measurements over the SGP ARM Central Facility Dong, X., and Smith, W.L. Jr., Analytical Services and Materials, Inc.; Minnis, P., NASA Langley Research Center Eighth Atmospheric Radiation Measurement (ARM) Science Team Meeting For reliable application of satellite datasets in cloud process and single column models, it is important to have a reasonable estimate of the errors in the observed cloud properties. When properly used, ground-based instruments can provide a cloud truth dataset for estimating errors in the satellite products. Data taken during the spring 1994 ARM Intensive Observation Period (IOP), ARM Enhanced Shortwave Experiment (ARESE), and SUbsonic Aircraft Contrail and Cloud Effects Special Study (SUCCESS) are

115

1  

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Lidar-Based Retrievals of the Microphysical Properties of Lidar-Based Retrievals of the Microphysical Properties of Mixed-Phase Arctic Stratus Clouds and Precipitation G. de Boer and E. Eloranta The University of Wisconsin Madison, Wisconsin Abstract The University of Wisconsin Arctic High Spectral Resolution Lidar has acquired months of continuous measurements in two high Arctic locations. These measurements have been combined with those taken by a National Oceanic and Atmospheric Administration - Environmental Technological Laboratory millimeter wave cloud radar to establish a long-range data set of cloud microphysical property retrievals. These properties include effective particle size, number density, and water content. Examples from this data set for arctic stratus are reviewed here, along with the methodology used in the retrievals.

116

frisch(2)-99.PDF  

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Radar/Radiometer Retrievals of Stratus Radar/Radiometer Retrievals of Stratus Cloud Liquid Water Content Profiles with In Situ Measurements by Aircraft A. S. Frisch Cooperative Institute for Research in the Atmosphere Colorado State University Boulder, Colorado B. E. Martner National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado I. Djalalova Science Technology Corporation Albuquerque, New Mexico M. R. Poellot Department of Atmospheric Sciences University of North Dakota Grand Forks, North Dakota Introduction Although most meteorological radars lack the sensitivity to detect small cloud droplets, recent advances in millimeter-wave cloud radars provide new opportunities for monitoring the properties of non-precipitating clouds by remote sensing. The problem of retrieving the microphysical features of

117

ARM - Feature Stories and Releases Article  

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January 31, 2005 [Facility News] January 31, 2005 [Facility News] Mobile Facility Beta Testing Complete; System Headed to California Seashore Bookmark and Share A key addition to the ARM Climate Research Facility scientific infrastructure is ready to roll...literally. In February, the ARM Mobile Facility (AMF) is being packed up and shipped from Richland, Washington, to the Point Reyes National Seashore north of San Francisco, California. There, it will be reassembled in preparation for its first deployment as part of a 6-month experiment to study the microphysical characteristics of marine stratus clouds, and in particular, marine stratus drizzle processes. Throughout the deployment, the AMF will accommodate aerosol observing equipment for National Oceanic and Atmospheric Administration (NOAA)

118

Four-Dimensional Data Assimilation D. Westphal, B. Toon, E. Jensen, S. Kinne, A. Ackerman,  

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D. Westphal, B. Toon, E. Jensen, S. Kinne, A. Ackerman, D. Westphal, B. Toon, E. Jensen, S. Kinne, A. Ackerman, R. Bergstrom, and A. Walker National Aeronautics and Space Administration Ames Research Center Moffett Field, CA 94035 Introduction Atmospheric Radiation Measurement (ARM) Program research at NASA Ames Research Center (ARC) includes radiative transfer modeling, cirrus cloud microphysics, and stratus cloud modeling. These efforts are designed to provide the basis for improving cloud and radiation parameterizations in our main effort: mesoscale cloud modeling. Radiative transfer modeling is described by Kinne et al. (this meeting); stratus and cirrus cloud modeling efforts are described by Toon et al. (this meeting); and mesoscale modeling is described in this abstract. Cloud Models for ARM optical properties. The last class of model listed in the table

119

1  

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Contrasting Properties of Single-Layer and Multi-Layer Contrasting Properties of Single-Layer and Multi-Layer Arctic Stratus Sampled During the Mixed-Phase Cloud Experiment G. Zhang and G.M. McFarquhar University of Illinois Urbana, Illinois J. Verlinde The Pennsylvania State University University Park, Pennsylvania M. Poellot University of North Dakota Grand Forks, North Dakota A. Heymsfield National Center for Atmospheric Research Boulder, Colorado Introduction The microphysical properties of both single-layer and multi-layer Arctic boundary layer stratus sampled during Mixed-Phase Cloud Experiment (M-PACE) are studied. In situ measurements are used to determine how cloud properties, such as phase, size distribution and shape of cloud particles, vary as a function of normalized cloud altitude (Z

120

EAC Meeting Summary October 16, 2012  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Capital Hilton Hotel Capital Hilton Hotel Washington, DC October 16, 2012 Summary of Meeting EAC Members in Attendance: WILLIAM BALL, Southern Company LINDA BLAIR, ITC Holdings Corp RICK BOWEN, Alcoa MERWIN BROWN, California Institute for Energy and Environment PAUL CENTOLELLA, former commissioner, Ohio, now with The Analysis Group RICHARD COWART, Chair of the EAC, Regulatory Assistance Project ROBERT CURRY, former commissioner, New York, now with Curry Energy CLARK GELLINGS, Electric Power Research Institute DIAN GRUENEICH, former commissioner, California, now with Grueneich Consulting MICHAEL HEYECK, American Electric Power PAUL HUDSON, former commissioner, Texas; now with Stratus Energy Group SUSAN KELLY, American Public Power Association BARRY LAWSON, National Rural Electric Cooperative Association

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121

U.S. Department of Energy Electricity Advisory Committee Meeting  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Meeting Meeting NRECA Conference Center Arlington, VA June 5, 2013 Summary of Meeting 2 PARTICIPANTS EAC: BILLY BALL Southern Company LINDA BLAIR Executive Vice President, ITC Holdings MERWIN BROWN California Institute for Energy & Environment PAUL CENTOLELLA Vice President, Analysis Group BOB CURRY Commissioner Emeritus, NY; Charles River Associates CLARK GELLINGS Electric Power Research Institute DIAN GREUNICH Dian Greunich Consulting PAUL HUDSON Stratus Energy Group, Austin SUE KELLY American Public Power Association RALPH MASIELLO DNV KEMA RICH MEYER (for BARRY LAWSON) National Rural Electric Cooperative Association CLAIR MOELLER Midcontinent Independent System Operator GRANGER MORGAN Carnegie Mellon, Engineering & Public Policy

122

ACARS Aerodynamic (Research Incorporated) Communication and Recording System  

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ix ix Acrononyms and Abbreviations Acronyms and Abbreviations ACARS Aerodynamic (Research Incorporated) Communication and Recording System ACSYS Arctic Climate System Study AER Atmospheric Environmental Research, Inc. AERI Atmospheric Emitted Radiance Interferometer AFOSR Air Force Office of Scientific Research AGARD Advisory Group for Aerospace Research and Development ALFA AER Local Forecast and Assimilation (model) AMIP Atmospheric Model Intercomparison Project ARCS Atmosphere Radiation and Cloud Stations ARCSS Arctic System Science (NSF) ARCSYM Arctic Regional Climate System Model ARINC Aerodynamic Research Incorporated Communication ARM Atmospheric Radiation Measurement program AS anvil stratus ASTER Atmosphere-Surface Turbulent Exchange Research ASTEX Altantic Stratocumulus Transition EXperiment

123

2012-2013 EAC Membership Roster  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

August 3, 2012 August 3, 2012 Electricity Advisory Committee 2012/2013 Membership Roster Richard Cowart Regulatory Assistance Project CHAIR Irwin Popowsky Pennsylvania Consumer Advocate VICE CHAIR William Ball Southern Company Linda Blair ITC Holdings Corporation Rick Bowen Alcoa Merwin Brown California Institute for Energy and Environment Ralph Cavanagh Natural Resources Defense Council The Honorable Paul Centolella Public Utilities Commission of Ohio David Crane NRG Energy, Inc. The Honorable Robert Curry New York State Public Service Commission Clark Gellings Electric Power Research Institute Dian Grueneich Dian Grueneich Consulting, LLC. Michael Heyeck American Electric Power Paul Hudson Stratus Energy Group Val Jensen Commonwealth Edison

124

Linkage of anthropogenic aerosol to clouds and climate. Progress report No. 3  

Science Conference Proceedings (OSTI)

During the first year of this project equipment was built to obtain direct droplet measurement data from a mobile platform in fog (or mountain impacted stratum) and to characterize CCN according to particle volatility (thermal processing). Since the start date, July 15, 1990, was during the California stratus season and it was necessary to complete the construction of equipment and allow time before a field project it was not possible to begin field work until the summer of 1991. This report discusses surface measurements made in 1991 and 1992 as well as the SEAHUNT (Shiptrail Evolution Above High Updraft Naval Targets) Project and the ASTEX (Atlantic Stratocumulus Transition Experiment) Project.

Hudson, J.G.

1992-12-14T23:59:59.000Z

125

EAC Meeting Summary October 15, 2012  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Electricity Advisory Committee Meeting Electricity Advisory Committee Meeting Capital Hilton Hotel Washington, DC October 15, 2012 Summary of Meeting EAC Members in Attendance: WILLIAM BALL, Southern Company LINDA BLAIR, ITC Holdings Corp RICK BOWEN, Alcoa MERWIN BROWN, California Institute for Energy and Environment PAUL CENTOLELLA, former commissioner, Ohio, now with The Analysis Group RICHARD COWART, Chair of the EAC, Regulatory Assistance Project ROBERT CURRY, former commissioner, New York, now with Curry Energy CLARK GELLINGS, Electric Power Research Institute DIAN GRUENEICH, former commissioner, California, now with Grueneich Consulting MICHAEL HEYECK, American Electric Power PAUL HUDSON, former commissioner, Texas; now with Stratus Energy Group SUSAN KELLY, American Public Power Association

126

Electricity Advisory Committee  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

December 20, 2012 December 20, 2012 Electricity Advisory Committee 2012 Membership Roster Richard Cowart Regulatory Assistance Project CHAIR Irwin Popowsky Pennsylvania Consumer Advocate (Ret.) VICE CHAIR William Ball Southern Company Linda Blair ITC Holdings Corporation Rick Bowen Alcoa Merwin Brown California Institute for Energy and Environment Ralph Cavanagh Natural Resources Defense Council Paul Centolella Analysis Group The Honorable Robert Curry New York State Public Service Commission Clark Gellings Electric Power Research Institute Dian Grueneich Dian Grueneich Consulting, LLC. Michael Heyeck American Electric Power Paul Hudson Stratus Energy Group Val Jensen Commonwealth Edison Susan Kelly American Public Power Association Barry Lawson

127

The PreVOCA experiment: Modeling the Lower Troposphere in the Southeast Pacific  

Science Conference Proceedings (OSTI)

The Preliminary VOCALS Model Assessment (PreVOCA) aims to assess contemporary atmospheric modeling of the subtropical South East Pacific, with a particular focus on the clouds and the marine boundary layer (MBL). Models results from fourteen modeling centers were collected including operational forecast models, regional models, and global climate models covering the month of October 2006. Forecast models and global climate models produced daily forecasts, while most regional models were run continuously during the study period, initialized and forced at the boundaries with global model analyses. Results are compared in the region from 40S to the equator and from 110W to 70W. Mean-monthly model surface winds agree well with QuikSCAT observed winds and models agree fairly well on mean weak large-scale subsidence in the region near the South American coast. However they have greatly differing mean geographic patterns of cloud fraction with only a few models agreeing well with MODIS observations. Most models also underestimate the boundary layer depth by several hundred meters in the eastern part of the study region. The modeled diurnal cycle of liquid water path is underestimated by most models at the 85W 20S stratus buoy compared with satellite, consistent with previous modeling studies. The low cloud fraction is also underestimated during all parts of the diurnal cycle compared with surface-based climatologies. Most models qualitatively capture the boundary layer deepening around 15 Oct 2006 at the stratus buoy, associated with colder air at 700hPa.

Wyant, M. C.; Wood, R.; Bretherton, Christopher S.; Mechoso, C. R.; Bacmeister, J.; Balmaseda, M. A.; Barrett, B.; Codron, F.; Earnshaw, P.; Fast, Jerome D.; Hannay, Cecile; Kaiser, J. W.; Kitagawa, H.; Klein, Stephen A.; Kohler, M.; Manganello, J.; Pan, H. L.; Sun, F.; Wang, S.; Wang, Yuqing

2010-05-26T23:59:59.000Z

128

Final technical Report DE-FG02-06ER65187  

SciTech Connect

Simulations from the University of Wisconsin Non-Hydrostatic Modeling System (UW-NMS) along with those from other models indicate a strong tendency to overproduce ice, resulting in a decimation of the liquid portion of mixed-phase stratus through the Bergeron-Findeissen process. Immersion freezing was illustrated to be a major contributor to ice production within these cloud layers, and aerosol properties were illustrated to be an important consideration in the simulation of this process. In particular, the soluble mass fraction and aerosol insoluble mass type were demonstrated to influence simulation of the immersion freezing process, Data collected by the Arctic High Spectral Resolution Lidar and Millimeter Cloud Radar during the M-PACE period was analyzed in order to provide a statistical dataset for validation of simulations of mixed-phase stratus. 270 hours of single-layer cases were reviewed, and mean values for cloud base height, cloud thickness, cloud optical thickness, cloud temperature, wind direction, and liquid and ice particle size, particle number density, and water content were derived.

Edwin Eloranta

2009-07-17T23:59:59.000Z

129

Hierarchical Diagnosis R. A. Kropfli, S. Y. Matrosov, T. Uttal, and B. W. Orr  

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

R. A. Kropfli, S. Y. Matrosov, T. Uttal, and B. W. Orr R. A. Kropfli, S. Y. Matrosov, T. Uttal, and B. W. Orr National Oceanic and Atmospheric Administration/Environmental Research Laboratories Wave Propagation Laboratory Boulder, CO 80303 I ntrod uction The WPL 8-mm wavelength radar was designed with good sensitivity and resolution to observe the small-scale structure and microphysical properties of clouds. DuringASTEX, for example, it observed, with 37-m resolution, all marine boundary layer (MBL) stratus and stratocumulus clouds within 5 km of the radar. More dense nonprecipitating clouds and very light drizzle were routinely observed to ranges exceeding 35 km. Characteristics of the radar are summarized in Table 1. A new offset Cassegrain antenna with good polarization performance is now being developed for this radar to study

130

Posters  

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Posters Stratus Cloud Measurements with a K α -Band Doppler Radar and a Microwave Radiometer A. S. Frisch, C. W. Fairall, and J. B. Snider National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado D. H. Lenschow National Center for Atmospheric Research Boulder, Colorado The goal of the Atlantic Stratocumulus Transition Experiment (ASTEX) held in the North Atlantic during June 1992 was to determine the physical reasons for the transition from stratocumulus to broken clouds. Some possible reasons for this transition were such things as cloud top entrainment instability (Randall 1980; Betts and Ridgway 1989) and the decoupling effects of drizzle (Albrecht 1989). As part of this experiment, the Environmental Technology Laboratory's cloud sensing Doppler radar and

131

Research Highlight  

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Simulating Mixed-Phase Clouds: Sensitivity to Ice Initiation Simulating Mixed-Phase Clouds: Sensitivity to Ice Initiation Download a printable PDF Submitter: Sednev, I., Lawrence Berkeley National Laboratory Menon, S., Lawrence Berkeley National Laboratory McFarquhar, G., University of Illinois, Urbana Area of Research: General Circulation and Single Column Models/Parameterizations Working Group(s): Cloud Modeling Journal Reference: I Sednev, S Menon, and G McFarquhar. 2008. "Simulating mixed-phase Arctic stratus clouds: Sensitivity to ice initiation mechanisms." Atmospheric Chemistry and Physics Discussion 8: 11755-11819. The vertical structure and radiative properties of persistent low-level Arctic clouds depend on their microphysics, and thus, estimation of the relative significance of the microphysical processes that occur in these

132

X:\ARM_19~1\PG93-112.WPD  

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

Figure 1. Drizzle parameters. The data for these measurements were taken on Figure 1. Drizzle parameters. The data for these measurements were taken on June 6, 1992, at 6 am. The first three Doppler moments from the vertically pointing radar were used in a log-normal three parameter cloud droplet model to determine the vertical profiles of modal radius, the standard deviation, and the number of droplets. Island Based Radar and Microwave Radiometer Measurements of Stratus Cloud Parameters During the Atlantic Stratocumulus Transition Experiment (ASTEX) A. S. Frisch C. W. Fairall and J. B. Snider CIRA Colorado State University NOAA Environmental Technology Laboratory Fort Collins, Colorado Boulder, Colorado D. H. Lenshow and S. D. Mayer National Center for Atmospheric Research Boulder, Colorado Introduction During the Atlantic Stratocumulus Transition Experiment

133

ARM - Field Campaign - MASRAD: Cloud Study from the 2NFOV at Pt. Reyes  

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govCampaignsMASRAD: Cloud Study from the 2NFOV at Pt. Reyes Field govCampaignsMASRAD: Cloud Study from the 2NFOV at Pt. Reyes Field Campaign Campaign Links AMF Point Reyes Website Related Campaigns MArine Stratus Radiation Aerosol and Drizzle (MASRAD) IOP 2005.03.14, Miller, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : MASRAD: Cloud Study from the 2NFOV at Pt. Reyes Field Campaign 2005.06.02 - 2005.09.30 Lead Scientist : Warren Wiscombe For data sets, see below. Description Cloud optical depth is one of the most important cloud optical properties, and vital for any cloud-radiation parameterization. Our ARM Science Team project has pioneered an algorithm to retrieve cloud optical depth in a fully three-dimensional cloud situation using zenith radiances from the ARM

134

arm_poster_eitzen.ppt  

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

Spearman Rank Correlations Between Boundary-layer Cloud Properties Spearman Rank Correlations Between Boundary-layer Cloud Properties Zachary A. Eitzen, SSAI and Kuan-Man Xu, NASA-LaRC 1. Cloud Object Data The cloud object data were taken from CERES-TRMM, over Jan-Aug 1998. Each boundary-layer cloud object is a contiguous region of CERES footprints that have cloud tops below 3 km, and a cloud fraction of: 99-100% (stratus), 40- 99% (stratocumulus), or 10-40% (shallow cumulus). The cloud objects in this work were all observed over the ocean, and within 30 degrees of the Equator. 2. Joint PDFs and Correlations We are not only interested in 1-D distributions of cloud properties (see Xu et al. 2007), but also how they change with one another. One way to examine this is with 2-D (joint) PDFs. However, with a large number of cloud properties, a

135

BNL | RACORO  

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RACORO Field Campaign RACORO Field Campaign Boundary layer clouds include stratus, stratocumulus, and fair-weather cumulus. Such clouds are ubiquitous over many parts of the globe and strongly influence the Earth's radiative energy balance. Our understanding of these clouds is insufficient to solve pressing scientific problems. The need for a better understanding of boundary layer clouds can only be achieved by acquiring high-quality in situ data that can be applied to process studies, fine-scale model evaluation, and the refinement of retrieval algorithms. A first-of-a-kind, extended-term cloud aircraft campaign was conducted to obtain an in situ statistical characterization of continental boundary-layer clouds. Coordinated by the Atmospheric Radiation Measurement (ARM) Aerial Facility (AAF), the Routine AAF Clouds with Low

136

Research Highlight  

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

Validation of CERES-MODIS Cloud Properties Using ARM Data Validation of CERES-MODIS Cloud Properties Using ARM Data Submitter: Dong, X., University of North Dakota Area of Research: Cloud Distributions/Characterizations Working Group(s): Cloud Properties Journal Reference: Dong, X., P. Minnis, B. Xi, S. Sun-Mack, and Y. Chen, 2007: Validation of CERES-MODIS stratus cloud properties using ground-based measurements at the DOE ARM SGP site. Accepted by J. Geophys. Res. Wielicki, B. A. and Co-authors (2000), CERES Validation Plan Overview, Release 4, 10/20/00, 58 pp. (Available at http://asd-www.larc.nasa.gov/ceres/validation/ ceresval_r4.0_over.pdf) Figure 1. Time series of surface-derived cloud-base and -top heights and temperatures (1-hour average) and matched MODIS-derived effective cloud heights and temperatures (30-km x 30-km box) for daytime single-layer and

137

1  

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

Further Estimates of the Error in the Retrieval Further Estimates of the Error in the Retrieval of Cloud Radar Effective Radius A. S. Frisch National Oceanic and Atmospheric Administration Environmental Technology Laboratory Colorado State University Boulder, Colorado M. D. Shupe and I. Djalalova Science Technology Corporation Boulder, Colorado M. R. Poellot Department of Atmospheric Sciences University of North Dakota Grand Forks, North Dakota Introduction We use aircraft Forward Scattering Spectrometer Probe (FSSP) data taken near the Southern Great Plains (SGP) site and during the ISCCP (First International Satellite Cloud Climatology Project) Regional Experiment-Arctic Cloud Experiment (FIRE-ACE) program in the Arctic to estimate a radar reflectivity retrieval of a stratus cloud effective radius (r

138

Posters A One-Dimensional Radiative Convective Model with Detailed Cloud Microphysics  

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5 5 Posters A One-Dimensional Radiative Convective Model with Detailed Cloud Microphysics J. Simmons, O. Lie-Svendsen, and K. Stamnes Geophysical Institute University of Alaska Fairbanks, Alaska The Arctic is a key element in determining the radiation budget of the earth. Within the polar regions, the net radiation (incoming solar radiation minus outgoing infrared radiation) is negative. To understand the role this energy deficit plays in the overall radiation budget, one must examine the prevalent atmospheric features of the Arctic. One such feature is a persistent layer of low-altitude, stratiform clouds found over the central Arctic predominantly from April to September (Tsay et al. 1984). These Arctic stratus clouds (ASC) modulate the earth's radiation budget

139

X:\ARM_19~1\P317-334.WPD  

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

Figure 1. Plot of the time of maximum wind speed (UTC) from the low-level jets Figure 1. Plot of the time of maximum wind speed (UTC) from the low-level jets observed using the ARM program 915-MHZ radar wind profiler vs. the height of this maximum wind speed (m). Summertime Low-Level Jets Over the Great Plains D. J. Stensrud NOAA/ERL/National Severe Storms Laboratory Norman, Oklahoma S. Pfeifer University of Oklahoma Norman, Oklahoma Introduction The sky over the southern Great Plains Cloud and Atmospheric Radiation Testbed (CART) site of the Atmospheric Radiation Measurement (ARM) Program during the predawn and early morning hours often is partially obstructed by stratocumulus, stratus fractus, or cumulus fractus that are moving rapidly to the north, even though the surface winds are weak. This cloud movement is evidence of the low-level jet (LLJ), a wind speed

140

Hierarchical Diagnosis  

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Development of a Rad iative Cloud Development of a Rad iative Cloud Parameterization Scheme of Stratocumulus and Stratus Clouds Which Includes the Impact of Cloud Condensation Nucleus on Cloud Albedo W. R. Cotton, G. L. Stephens, D. Duda, B. Stevens, and R. L. Walko Colorado State University Department of Atmospheric Science Fort Collins, CO G. Feingold Cooperative Institute for Research in Environmental Sciences University of Colorado, Boulder Boulder. CO 80309-0049 A three-dimensional (3-D) model for simulating the effect of enhanced cloud condensation nucleus (CCN) concentrations on stratocumulus clouds is presented. Results of two-dimensional (2-D) tests are discussed for a control run and a sensitivity run where CCN spectra were taken to be typical of clean marine conditions or mildly continental air, respectively. For a fivefold increase in

Note: This page contains sample records for the topic "mase-marine stratus experiment-pt" 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
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141

ARM - Publications: Science Team Meeting Documents  

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

Meeting Meeting 2003 Proceedings Proceedings Sorted by Title Proceedings Sorted by Author Science Team Meeting Proceedings Cover image Proceedings of the Thirteenth Atmospheric Radiation Measurement (ARM) Science Team Meeting ARM-CONF-2003, April 2003 Broomsfield, Colorado For proper viewing, extended abstracts should be viewed with Adobe Acrobat Reader. Download the latest version from the Adobe Reader website. View session papers by Author or Title. * Poster abstract only; an extended abstract was not provided by the author(s). A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A Abdou, W.A. Intercomparison of MISR Aerosol Retrievals with Sunphotometer and MODIS Results* Ackerman, T.P. Comparison of Observed and Modelled Liquid Water Path for Stratus and Stratocumulus Clouds at the SGP*

142

Radiosonde observations at Pt. Reyes and cloud properties retrieved from  

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Radiosonde observations at Pt. Reyes and cloud properties retrieved from Radiosonde observations at Pt. Reyes and cloud properties retrieved from GOES-WEST Inoue, Toshiro MRI/JMA Category: Field Campaigns Low-level cloud formed off the west coast of continents plays an important role in general circulation and climate. Marine Stratus Radiation Aerosol and Drizzle (MASRAD) was conducted at the ARM mobile site deployed at Pt Reyes, California during April to September. Here, we studied the relationship between meteorological parameters observed by GPS sonde and cloud properties observed from GOES-WEST during the MASRAD intensive operational period. Cloud properties are retrieved from VISST (Visible Infrared Solar-infrared Split window Technique). The vertical profile of stability, relative humidity (RH) and wind speed observed by GPS sonde are

143

ARM2007_STM_poster_v1  

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Liquid Stratiform Clouds-Aerosol Interaction Liquid Stratiform Clouds-Aerosol Interaction The consistently steady and thin maritime stratus clouds observed at Pt. Reyes are much closer to adiabatic, mostly in uenced by the stronger static stability and drier condition above the cloud. These clouds shows the better e cacy of aerosol-cloud interactions since they form in a much more homogeneous meteorological (low variability in LWP) and less entrainment-driven environment than those at the continental site. There are still some limitations on observation artifacts and uncertainty in estimating adiabaticity based on the remote sensing. Conclusions This Study Suppression of LWP Variability E cacy of Aerosol - Cloud Interactions under Varying Meteorological Conditions Byung-Gon Kim @

144

ARM - Publications: Science Team Meeting Documents  

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Meeting Meeting 1999 Proceedings Proceedings Sorted by Title Proceedings Sorted by Author Science Team Meeting Proceedings Cover image Proceedings of the Ninth Atmospheric Radiation Measurement (ARM) Science Team Meeting ARM-CONF-1999, March 1999 San Antonio, Texas For proper viewing, many of these proceedings should be viewed with Adobe Acrobat Reader. Download the latest version from the Adobe Reader website. View session papers by Author or Title. * Poster abstract only; an extended abstract was not provided by the author(s). A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A Abshire, J.B. Development of a Compact Lidar to Profile Water Vapor in the Lower Troposphere Ackerman, T.P. A 25-Month Database of Stratus Cloud Properties Generated from Ground-Based Measurements at the ARM SGP Site

145

This Study  

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This Study Several studies demonstrated aerosol indirect e ect such as modi cations of cloud properties due to aerosols and corresponding changes in shortwave and longwave radiative uxes. Some recent studies indicated aerosol indirect e ects may not be the primary modulator of cloud optical properties in certain situations. They implied other processes were impacting the cloud optical properties (Kim et al., JGR 2003). To study these other impacts, we extend a previous study to investigate the role of adiabaticity facilitated by mixing in modulating cloud optical properties. We quantify the e ects of mixing by measuring the ratio of the observed cloud water path to its adiabatic value, (adiabaticity, α). The screening criteria for relatively homogeneous stratus

146

ARM - Facility News Article  

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30, 2005 [Facility News] 30, 2005 [Facility News] Coastal Clouds Field Campaign Takes Off in July Bookmark and Share The 2-channel NFOV gets careful attention as it joins the suite of instruments collecting data for the ARM Mobile Facility field campaign at Point Reyes National Seashore. The 2-channel NFOV gets careful attention as it joins the suite of instruments collecting data for the ARM Mobile Facility field campaign at Point Reyes National Seashore. Since March 2005, the ARM Mobile Facility (AMF) has been at Point Reyes National Seashore in northern California for the Marine Stratus Radiation, Aerosol, and Drizzle Intensive Operational Period. The goals of this 6-month field campaign are to collect data from cloud/aerosol interactions and to improve understanding of cloud organization that is often associated

147

Research Highlight  

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Profiling Capability of High-Resolution Oxygen A-band Spectroscopy for Profiling Capability of High-Resolution Oxygen A-band Spectroscopy for Stratus Cloud Cover Submitter: Davis, A. B., Jet Propulsion Laboratory Area of Research: Cloud Distributions/Characterizations Working Group(s): Cloud Properties Journal Reference: Davis AB, IN Polonsky, and A Marshak. 2009. Space-Time Green Functions for Diffusive Radiation Transport, in Application to Active and Passive Cloud Probing. In Light Scattering Reviews, Volume 4, pp. 169-292. Ed. by A.A. Kohkanovsky, Heidelberg, Germany: Springer. Transmission: (a) Ratio of mean path Τ to cloud thickness Η times (1-g)τ plotted versus cosine of SZA μ0 and cloud optical depth τ; asymmetry factor g was set to 0.85, then delta-rescaled to 0.46. Given this ratio (>1/2) and Η or τ, one can infer the other cloud parameter.

148

Research Highlight  

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Buffering of Ice Crystal Number Concentration to Ice Nucleus Abundance Buffering of Ice Crystal Number Concentration to Ice Nucleus Abundance Above Arctic Stratus Download a printable PDF Submitter: Fridlind, A. M., NASA - Goddard Institute for Space Studies Ackerman, A., NASA - Goddard Institute for Space Studies Area of Research: Cloud Processes Working Group(s): Cloud-Aerosol-Precipitation Interactions Journal Reference: Fridlind AM, B van Diedenhoven, AS Ackerman, A Avramov, A Mrowiec, H Morrison, P Zuidema, and MD Shupe. 2012. "A FIRE-ACE/SHEBA case study of mixed-phase Arctic boundary-layer clouds: Entrainment rate limitations on rapid primary ice nucleation processes." Journal of the Atmospheric Sciences, 69(1), doi:10.1175/JAS-D-11-052.1. Observed and simulated histograms of MMCR radar reflectivity (left) and

149

ARM - Field Campaign - Cloud IOP  

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govCampaignsCloud IOP govCampaignsCloud IOP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Cloud IOP 1998.04.27 - 1998.05.17 Lead Scientist : Gerald Mace For data sets, see below. Summary Monday, April 27, 1998 IOP Opening Activities: Heavy rain (nearly 2.5" since 12Z 4/26/98) at the central facility (CF) dominated the first day of the Cloud Physics/Single Column Model IOP and limited the daily activities. A 1430 GMT sonde launch commenced the 3-hour sonde launch schedule at the CF and 4 boundary facilities (BFs). Scientists/Instrumentation on Site: Citation: Has arrived and is located at the Ponca City Airport. No flights are currently planned. Flights are tentatively planned for stratus sampling when precipitation ends.

150

ARM - Facility News Article  

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Guest Instruments to Collect Aerosol Data During Coastal Field Campaign Guest Instruments to Collect Aerosol Data During Coastal Field Campaign Bookmark and Share The counter-flow virtual impactor (inset), which can characterize aerosol particles in cloud droplets, joins a number of other guest instruments at the ARM Mobile Facility deployment site at Point Reyes National Seashore in California. The counter-flow virtual impactor (inset), which can characterize aerosol particles in cloud droplets, joins a number of other guest instruments at the ARM Mobile Facility deployment site at Point Reyes National Seashore in California. The ARM Mobile Facility's (AMF's) inaugural field campaign, the Marine Stratus Radiation Aerosol and Drizzle (MASRAD) Intensive Operational Period, is well underway at Point Reyes National Seashore on the northern

151

MotorWeek Video Transcript: Dodge Avenger FFV  

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Dodge Avenger FFV Dodge Avenger FFV The Avenger nameplate has dressed its share of metal over the years. Now, it finds it marquee on a midsize four-door that Dodge hopes will sway a meaningful slice of family sedan sales into their direction. But it will take more than powerfully carved curves and heady nameplate for this Avenger to become a hero. As Dodge aimed to build a replacement for its mid-size Stratus family sedan, they stepped forth with the same boldness that defines the rest of their line-up. Taking cues from tigers and boxing gloves, Dodge brings to fruition the all-new sport-infused 2008 Avenger sedan. Available in four trims, SE, SXT, our RT and RT AWD, the Avenger boasts the same Dodge "gotcha" attitude as the full-size Charger. Aggression oozes from the brand's signature crosshair grille and the

152

1  

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Factors Controlling the Properties of Multi-Phase Factors Controlling the Properties of Multi-Phase Arctic Stratocumulus Clouds A. Fridlind and A. Ackerman National Aeronautics and Space Administration - Ames Research Center Moffett Field, California S. Menon and I. Sednev Lawrence Berkeley National Laboratory Berkeley, California Introduction The October 2004 Multi-Phase Arctic Cloud Experiment (M-PACE) Intensive Operational Period (IOP) at the Atmospheric Radiation Measurement (ARM) Climate Research Facility's (ACRF's) North Slope of Alaska (NSA) locale focused on measuring the properties of autumn transition-season arctic stratus and the environmental conditions controlling them, including concentrations of heterogeneous ice nuclei. Our work aims to use a large-eddy simulation (LES) code with embedded size-resolved cloud

153

Using ARM data to correct plane-parallel satellite retrievals of cloud  

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Using ARM data to correct plane-parallel satellite retrievals of cloud Using ARM data to correct plane-parallel satellite retrievals of cloud properties Dong, Xiquan University of North Dakota Minnis, Patrick NASA Langley Research Center Xi, Baike University of North Dakota Khaiyer, Mandana Analytical Services and Material, Inc. Category: Cloud Properties The angular variations of cloud properties derived from GOES data are examined using simultaneously collocated ARM surface observations/retrievals at the DOE ARM SGP site during the 6-yr period from January 1997 to December 2002. The dependencies of GOES cloud retrievals on solar zenith angle (SZA), scattering angle (SCA), and relative azimuth angle (RZA) are investigated for single-layer and overcast low-level stratus clouds. The GOES-retrieved cloud-droplet effective radius (re),

154

Research Highlights Sorted by Submitter  

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Submitter Submitter A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A Ackerman, A. Buffering of Ice Crystal Number Concentration to Ice Nucleus Abundance above Arctic Stratus ARM To Be or Not To Be Liquid? The Challenge of Arctic Mixed-Phase Cloud Modeling ARM Tropical Rain Clouds Still a Challenge to Cloud-Resolving Models ARM ASR Understanding Ice Formation in Arctic Mixed-Phase Boundary-Layer Clouds During ISDAC ARM Ackerman, T. P. Progress in Understanding Water Vapor's Role in Models ARM Quantifying the Magnitude of Anomalous Solar Absorption ARM Shortwave Absorption in Tropical Clouds ARM Structure of Cirrus Properties and its Coupling with the State of the Large-Scale Atmosphere ARM The k-Distribution Method for a SW Radiative Transfer Model ARM Ahlgrimm, M.

155

ARM - Publications: Science Team Meeting Documents  

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A Comparison of Surface Sensible Heat Flux at Atqasuk and Barrow A Comparison of Surface Sensible Heat Flux at Atqasuk and Barrow Shaw, W.J. (a), Doran, J.C. (b), and Hubbe, J.M. (c), Pacific Northwest National Laboratory Eleventh Atmospheric Radiation Measurement (ARM) Science Team Meeting As part of the effort to discover the feedbacks between low-level arctic stratus and surface fluxes, we have operated an acoustic anemometer near Barrow, Alaska and a dual wavelength scintillometer near Atqasuk, which is 100 km to the south, in order to measure the surface turbulence heat flux. The systems operated unattended during the spring melt period of 2000, and the data were logged via internet or telephone connections. The acoustic anemometer was mounted on a tower attached to a barge grounded on a low island on the northeast side of Elson Lagoon. The anemometer was 8.5 m

156

1  

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Dual Polarization Observations on an MMCR: Dual Polarization Observations on an MMCR: Implementation and First Results K. P. Moran, T. Ayers, B. E. Martner, and M. J. Post National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado K. B. Widener Pacific Northwest National Laboratory Richland, Washington Introduction The Atmospheric Radiation Measurement (ARM) Program's millimeter-wavelength cloud radar (MMCR) is a super-sensitive device capable of measuring extremely weak signals backscattered from small ice crystals and water droplets. Its sensitivity allows the radar to observe thin high cirrus clouds containing small ice particles as well as low-altitude stratus clouds composed of tiny water droplets (Moran et al. 1998). Unfortunately, other particulates suspended in the atmosphere, such as insects, ash,

157

Research Highlight  

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How Aerosols Affect Cloud Properties in Arctic Mixed-Phase Stratocumulus How Aerosols Affect Cloud Properties in Arctic Mixed-Phase Stratocumulus Download a printable PDF Submitter: McFarquhar, G., University of Illinois, Urbana Area of Research: Cloud-Aerosol-Precipitation Interactions Working Group(s): Cloud-Aerosol-Precipitation Interactions Journal Reference: Jackson RC, GM McFarquhar, AV Korolev, ME Earle, PS Liu, RP Lawson, S Brooks, M Wolde, A Laskin, and M Freer. 2012. "The dependence of ice microphysics on aerosol concentration in arctic mixed-phase stratus clouds during ISDAC and M-PACE." Journal of Geophysical Research - Atmospheres, 117, D15207, doi:10.1029/2012JD017668. Cloud mean ice crystal concentration Nice(D ≥ 50 micrometers) versus mean aerosol concentration (NPCASP) above cloud for all 41 vertical profiles

158

kollias-99.PDF  

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Mass Flux Representations of Vertical Mass Flux Representations of Vertical Velocity Fluctuations in Continental Stratus Clouds Using a mm-Wavelength Doppler Radar P. Kollias and B. A. Albrecht University of Miami Miami, Florida Introduction A cloud mass flux representation of the vertical turbulent fluxes provides a physical framework for understanding the effects of shallow convection in maintaining the vertical structure of the boundary layer. This approach is based on the assumption that coherent updrafts and downdraft structures are responsible for most of the turbulent transport. Previous evaluations of mass flux parameterizations have been based on aircraft observations (e.g., Penc and Albrecht 1987) and results from Large Eddy Simulations (LESs) (e.g., Siebesma and Cuijpers 1995). In this study, mm-wavelength radar

159

1  

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Comparisons with the Cloud Radar Retrievals Comparisons with the Cloud Radar Retrievals of Stratus Cloud Effective Radius A. S. Frisch and G. Feingold Cooperative Institute for Research in the Atmosphere National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado M. D Shupe and I. Djalalova Science Technology Corporation National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado M. R. Poellot Department of Atmospheric Sciences University of North Dakota Grand Forks, North Dakota Abstract In situ sampling of cloud droplets by aircraft in Oklahoma in 1997, Surface Heat Budget of the Arctic Ocean (SHEBA) - First ISCCP Regional Experiment Aerosol Characterization Experiment (FIRE ACE) in 1998, and a collection of droplet spectra measured from various locations around the world are used

160

1  

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Continuous Flow Ice Thermal Diffusion Chamber Continuous Flow Ice Thermal Diffusion Chamber Measurements of Ice Nuclei in the Arctic A.J. Prenni, P.J. DeMott, and S.M. Kreidenweis Department of Atmospheric Science, Colorado State University Fort Collins, Colorado D.C. Rogers National Center for Atmospheric Research EOL/RAF Broomfield, Colorado Introduction Mixed-phase stratus clouds are ubiquitous in the Arctic and play an important role in climate in this region. However, climate and regional models have generally proven unsuccessful at simulating arctic cloudiness, particularly during the colder months. Specifically, models tend to under-predict the amount of liquid water in mixed-phase clouds. This is problematic because cloud phase can greatly impact the radiative budget. The Mixed-Phase Arctic Cloud Experiment (M-PACE), conducted from late

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161

Research Highlight  

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CCN and Vertical Velocity Influences CCN and Vertical Velocity Influences Submitter: Hudson, J. G., Desert Research Institute Area of Research: Cloud-Aerosol-Precipitation Interactions Working Group(s): Cloud-Aerosol-Precipitation Interactions Journal Reference: Hudson JG and S Noble. 2013. "CCN and vertical velocity influences on droplet concentrations and supersaturations in clean and polluted stratus clouds." Journal of the Atmospheric Sciences, , . ACCEPTED. Figure 1. Effective cloud supersaturation (Seff) against CCN concentration at 1% S (N1%) for horizontal cloud penetrations, 50 for MASE and 34 for POST. Seff is the S for which nearby below cloud CCN spectra, NCCN(S), equals mean droplet concentration (Nc). Figure 2. One second droplet concentration, Nc, and vertical velocity

162

ARM - Journal Articles 2003  

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3 3 Publications Journal Articles Conference Documents Program Documents Technical Reports Publications Database Public Information Materials Image Library Videos Publication Resources Submit a Publication Publishing Procedures ARM Style Guide (PDF, 448KB) Acronyms Glossary Logos Contacts RSS for Publications Journal Search [ Advanced Search ] Publication Years 2013 149 2012 163 2011 185 2010 197 2009 213 2008 174 2007 150 2006 213 2005 139 2004 141 2003 187 2002 205 2001 207 2000 232 1999 136 1998 172 1997 103 1996 84 1995 124 1994 65 1993 51 1992 47 1991 25 1990 12 1986 1 Journal Articles : 2003 Author Article Title Journal Funded By Dong Arctic stratus cloud properties and radiative forcing at the ARM NSA site (Citation) J. Climate ARM Zurovac-Jevtic Development and test of a cirrus parameterization scheme using NCAR CCM3 (Citation) Journal of the Atmospheric Sciences ARM

163

Research Highlight  

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Influence of Humidified Aerosols on Lidar Depolarization Below Influence of Humidified Aerosols on Lidar Depolarization Below Ice-Precipitating Arctic Clouds Download a printable PDF Submitter: Fridlind, A. M., NASA - Goddard Institute for Space Studies van Diedenhoven, B., NASA - Goddard Institute for Space Studies Area of Research: Cloud Distributions/Characterizations Working Group(s): Cloud Life Cycle Journal Reference: van Diedenhoven B, AM Fridlind, and AS Ackerman. 2011. "Influence of humidified aerosol on lidar depolarization measurements below ice-precipitating Arctic stratus." Journal of Applied Meteorology and Climatology, 50(10), doi:10.1175/JAMC-D-11-037.1. Correlated MMCR radar reflectivities and DABUL lidar depolarizations below cloud base calculated with a reasonably low number of large, coarse-mode

164

ARM - Publications: Science Team Meeting Documents  

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Preliminary Analysis of Horizontal Inhomogeneity for ARESE II Clouds Preliminary Analysis of Horizontal Inhomogeneity for ARESE II Clouds Marshak, A. (a), Wiscombe, W.J. (b), Davis, A.B. (c), and Pilewskie, P. (d), UMBC/JCET (a), NASA/GSFC (b), LANL (c), NASA/Ames (d) Eleventh Atmospheric Radiation Measurement (ARM) Science Team Meeting ARM Enhanced Shortwave Experiment (ARESE) II was conducted at the SGP site from February 21 through April 15, 2000. The identical set of radiometers simultaneously measured the broadband and narrowband fluxes, as well as spectral fluxes and radiances from the aircraft flying above clouds and on the ground. To escape sampling problems with only one aircraft flying a daisy pattern over the central facility, the whole experiment was focused on optically thick stratocumulus clouds. However, even heavy stratus clouds

165

miles-99.PDF  

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Vertical Velocity Statistics as Derived from 94-GHz Vertical Velocity Statistics as Derived from 94-GHz Radar Measurements N. L. Miles, D. M. Babb, and J. Verlinde The Pennsylvania State University University Park, Pennsylvania Introduction Profiles of millimeter-wavelength radar Doppler spectra contain information about both the mean vertical velocities and cloud microphysics. In order to obtain this information, it is necessary to remove the effects of turbulence. Stratocumulus clouds often contain various species of ice and liquid, including graupel, crystals, columns, plates, liquid droplets, and drizzle drops. Most of the previous work to remotely determine microphysics of stratus clouds has largely ignored the presence of drizzle and ice, restricting applicability to only liquid clouds with no drizzle, a relatively rare event. Since mixed phase

166

Microsoft Word - Poellot-MR.doc  

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Measurements of Cloud Liquid Water Over the SGP Site Measurements of Cloud Liquid Water Over the SGP Site M. R. Poellot University of North Dakota Grand Forks, North Dakota R. T. Marchand Pacific Northwest National Laboratory Richland, Washington C. Twohy Oregon State University Corvallis, Oregon Introduction The University of North Dakota Citation aircraft made in situ measurements of liquid water clouds on six flights in stratus clouds during the Spring 2000 Cloud Intensive Operational Period (IOP) at the Southern Great Plains (SGP) site. Four in situ instruments were used to measure cloud liquid water content (LWC): a particle measuring system (PMS) King liquid water sensor, a Counterflow Virtual Impactor (CVI), a PMS Forward Spectral Scattering Probe (FSSP) and a one-dimensional (1D) optical

167

Posters  

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3 3 Posters The Effects of Arctic Stratus Clouds on the Solar Energy Budget in the Atmosphere-Sea Ice-Ocean System Z. Jin and K. Stamnes Geophysical Institute University of Alaska Fairbanks, Alaska B. D. Zak Sandia National Laboratories Albuquerque, New Mexico Radiative Transfer Model We have developed a comprehensive radiative transfer model pertinent to the atmosphere-sea ice-ocean system (Jin and Stamnes 1994; Jin et al., in press). The main features of the newly-developed radiative transfer model include: * The atmosphere, sea ice, and ocean each represented by a sufficient number of layers to resolve the change in the optical properties of each stratum. * An appropriate quadrature structure to take into account the refraction and the total reflection at the air-ice or air-

168

Kogan-ZN  

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Drop Effective Radius for Drizzling Drop Effective Radius for Drizzling Marine Stratus in Global Circulation Models Z. N. Kogan and Y. L. Kogan Cooperative Institute for Mesoscale Meteorological Studies University of Oklahoma Norman, Oklahoma Introduction The cloud drop effective radius, R e , is one of the most important parameters in calculations of cloud radiative properties. Numerous formulations of the effective radius have been developed for use in numerical models (see, e.g., review in Gultepe et al. 1996); however, to the best of our knowledge, they all were designed for non-drizzling clouds. The objective of this paper is to derive a parameterization of R e for precipitating boundary layer clouds. The R e parameterization is necessarily a function of cloud prognostic variables used in a specific numerical model. To this regard, we note that the majority of

169

DOE/SC-ARM-P-07-006 Evaluation of Mixed-Phase Cloud Microphysics  

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6 6 Evaluation of Mixed-Phase Cloud Microphysics Parameterizations with the NCAR Single Column Climate Model (SCAM) and ARM Observations Second Quarter 2007 ARM Metric Report April 2007 Xiaohong Liu and Steven J. Ghan Pacific Northwest National Laboratory Richland, Washington Shaocheng Xie Lawrence Livermore National Laboratory Livermore, California Work supported by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research X. Lui, S.J. Ghan, and S. Xie, DOE/SC-ARM/P-07-006 Summary Mixed-phase stratus clouds are ubiquitous in the Arctic and play an important role in climate in this region. However, climate models have generally proven unsuccessful at simulating the partitioning of condensed water

170

X:\ARM_19~1\PGS1-8.WPD  

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Boundary-Layer Cloud Study Using Southern Great Boundary-Layer Cloud Study Using Southern Great Plains Cloud and Radiation Testbed (CART) Data B. Albrecht, G. Mace, X. Dong, W. Syrett, and T. Ackerman Pennsylvania State University, Department of Meteorology University Park, Pennsylvania Introduction Boundary layer clouds-stratus and fairweather cumulus- are closely coupled to the water and energy budgets of land surfaces. This coupling involves the radiative impact of the clouds on the surface energy budget and the strong dependence of cloud formation and maintenance on the turbulent fluxes of heat and moisture in the boundary layer. The continuous data collection at the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site provides a unique opportunity to study components of the coupling processes associated with boundary layer clouds

171

wangz-98.pdf  

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1 1 Ozone Destruction in Continental Stratus Clouds: Experimental Evidence for Heterogeneous Chemistry Z. Wang and K. Sassen Department of Meteorology University of Utah Salt Lake City, Utah Introduction There is considerable interest in studying tropospheric ozone because of its role as a greenhouse gas and as a key element in tropospheric chemistry. Heterogeneous chem- istry involving reactions with aerosols and cloud droplets can affect O 3 in a number of ways. The results of model studies show that aqueous phase chemistry is shown to decrease ozone concentrations significantly in the troposphere (Jacob 1986, 1997; Lelieveld and Crutzen 1990; Liang and Jacob 1997; and Matthijsenetal et al. 1997). Reichardt et al. (1996) and Sassen et al. (1998a) found pronounced O

172

Apparent spatial blurring and displacement of a point optical source due to cloud scattering  

Science Conference Proceedings (OSTI)

A Monte Carlo algorithm is used to determine the apparent spatial blurring of a terrestrial 1.07 micron optical point source due to cloud scattering as seen from space. The virtual image of a point source over a virtual source plane area 22.4 x 22.4 square kilometers arising from cloud scattering was determined for stratus clouds (NASA cloud number 5) and altostratus clouds optical source arises from photon scattering by cloud water droplets. Displacement of the virtual source is due to the apparent illumination of the cloud top region directly about the actual source which when viewed at a nonzero look angle gives a projected displacement of the apparent source relative to the actual source. These features are quantified by an analysis of the Monte Carlo computational results.

Brower, K.L.

1997-09-01T23:59:59.000Z

173

Four-Dimensional Data Assimilation O. B. Toon, A. Ackerman, and E. Jensen  

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O. B. Toon, A. Ackerman, and E. Jensen O. B. Toon, A. Ackerman, and E. Jensen National Aeronautics and Space Administration Ames Research Center Moffett Field, CA 94035 Center for Atmospheric Research (NCAR) mesoscale dynamical model and used to simulated cirrus clouds during the First ISCCpCa) Regional Experiment (FIRE) project. One of our goals in performing one-dimensional studies is to develop the microphysics for these three-dimensional simulations. However, since the microphysics itself is computationally very demanding, the one-dimensional simulations are often useful for cloud simulations of microphysics in situations in which dynamics either is not important or can be parameterized. Here we discuss only one-dimensional simulations. Marine stratus are the only clouds for which there are significant data showing effects of aerosols on cloud

174

ARM - Field Campaign - MASRAD: Cloud Condensate Nuclei Chemistry  

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govCampaignsMASRAD: Cloud Condensate Nuclei Chemistry Measurements govCampaignsMASRAD: Cloud Condensate Nuclei Chemistry Measurements Campaign Links AMF Point Reyes Website Related Campaigns MArine Stratus Radiation Aerosol and Drizzle (MASRAD) IOP 2005.03.14, Miller, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : MASRAD: Cloud Condensate Nuclei Chemistry Measurements 2005.07.01 - 2005.07.30 Lead Scientist : Carl Berkowitz For data sets, see below. Description Principal Investigators: J. Ogren, C. Berkowitz, R. Halthore, A. Laskin, A. Strawa, J. Wang, A. Wexler As part of the ARM Mobile Facility (AMF) deployment to Point Reyes, CA in the spring and summer of 2005, a suite of instrumentation was installed to measure the chemical, physical and optical properties of aerosol particles

175

kadygrov-98.pdf  

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Potential Performance of Boundary Layer Temperature Potential Performance of Boundary Layer Temperature Profile Microwave Remote Sensing: Results of Field Testing at Various Latitude Zones E. N. Kadygrov and K. P. Gaikovich Central Aerological Observatory Russia E. R. Westwater and Y. Han Cooperative Institute for Research in Environmental Sciences University of Colorado NOAA-Environmental Technology Laboratory Boulder, Colorado K. B. Widener Pacific Northwest National Laboratory Richland, Washington Introduction Remote sensing of low-altitude temperature profiles is important for a variety of studies, including the interaction between the atmosphere and the earth's surface, air pollution, dissipation of fog and stratus clouds, forecasting of the distribution and dispersion of gases emitted from low level sources into the free atmosphere, and short-term

176

Evaluation of Mixed-Phase Cloud Microphysics Parameterizations with the NCAR Single Column Climate Model (SCAM) and ARM Observations  

SciTech Connect

Mixed-phase stratus clouds are ubiquitous in the Arctic and play an important role in climate in this region. However, climate models have generally proven unsuccessful at simulating the partitioning of condensed water into liquid droplets and ice crystals in these Arctic clouds, which affect modeled cloud phase, cloud lifetime and radiative properties. An ice nucleation parameterization and a vapor deposition scheme were developed that together provide a physically-consistent treatment of mixed-phase clouds in global climate models. These schemes have been implemented in the National Center for Atmospheric Research (NCAR) Community Atmospheric Model Version 3 (CAM3). This report documents the performance of these schemes against ARM Mixed-phase Arctic Cloud Experiment (M-PACE) observations using the CAM single column model version (SCAM). SCAM with our new schemes has a more realistic simulation of the cloud phase structure and the partitioning of condensed water into liquid droplets against observations during the M-PACE than the standard CAM simulations.

Liu, X; Ghan, SJ; Xie, S

2007-04-01T23:59:59.000Z

177

Model simulations of the first aerosol indirect effect and comparison of cloud susceptibility fo satellite measurements  

DOE Green Energy (OSTI)

Present-day global anthropogenic emissions contribute more than half of the mass in submicron particles primarily due to sulfate and carbonaceous aerosol components derived from fossil fuel combustion and biomass burning. These anthropogenic aerosols modify the microphysics of clouds by serving as cloud condensation nuclei (CCN) and enhance the reflectivity of low-level water clouds, leading to a cooling effect on climate (the Twomey effect or first indirect effect). The magnitude of the first aerosol indirect effect is associated with cloud frequency as well as a quantity representing the sensitivity of cloud albedo to changes in cloud drop number concentration. This quantity is referred to as cloud susceptibility [Twomey, 1991]. Analysis of satellite measurements demonstrates that marine stratus clouds are likely to be of higher susceptibility than continental clouds because of their lower number concentrations of cloud drops [Platnick and Twomey, 1994]. Here, we use an improved version of the fully coupled climate/chemistry model [Chuang et al., 1997] to calculate the global concentrations Of sulfate, dust, sea salt, and carbonaceous aerosols (biomass smoke and fossil fuel organic matter and black carbon). We investigated the impact of anthropogenic aerosols on cloud susceptibility and calculated the associated changes of shortwave radiative fluxes at the top of the atmosphere. We also examined the correspondence between the model simulation of cloud susceptibility and that inferred from satellite measurements to test whether our simulated aerosol concentrations and aerosol/cloud interactions give a faithful representation of these features.

Chuang, C; Penner, J E; Kawamoto, K

2002-03-08T23:59:59.000Z

178

Final Technical Report for "Ice nuclei relation to aerosol properties: Data analysis and model parameterization for IN in mixed-phase clouds"? (DOE/SC00002354)  

Science Conference Proceedings (OSTI)

Clouds play an important role in weather and climate. In addition to their key role in the hydrologic cycle, clouds scatter incoming solar radiation and trap infrared radiation from the surface and lower atmosphere. Despite their importance, feedbacks involving clouds remain as one of the largest sources of uncertainty in climate models. To better simulate cloud processes requires better characterization of cloud microphysical processes, which can affect the spatial extent, optical depth and lifetime of clouds. To this end, we developed a new parameterization to be used in numerical models that describes the variation of ice nuclei (IN) number concentrations active to form ice crystals in mixed-phase (water droplets and ice crystals co-existing) cloud conditions as these depend on existing aerosol properties and temperature. The parameterization is based on data collected using the Colorado State University continuous flow diffusion chamber in aircraft and ground-based campaigns over a 14-year period, including data from the DOE-supported Mixed-Phase Arctic Cloud Experiment. The resulting relationship is shown to more accurately represent the variability of ice nuclei distributions in the atmosphere compared to currently used parameterizations based on temperature alone. When implemented in one global climate model, the new parameterization predicted more realistic annually averaged cloud water and ice distributions, and cloud radiative properties, especially for sensitive higher latitude mixed-phase cloud regions. As a test of the new global IN scheme, it was compared to independent data collected during the 2008 DOE-sponsored Indirect and Semi-Direct Aerosol Campaign (ISDAC). Good agreement with this new data set suggests the broad applicability of the new scheme for describing general (non-chemically specific) aerosol influences on IN number concentrations feeding mixed-phase Arctic stratus clouds. Finally, the parameterization was implemented into a regional cloud-resolving model to compare predictions of ice crystal concentrations and other cloud properties to those observed in two intensive case studies of Arctic stratus during ISDAC. Our implementation included development of a prognostic scheme of ice activation using the IN parameterization so that the most realistic treatment of ice nuclei, including their budget (gains and losses), was achieved. Many cloud microphysical properties and cloud persistence were faithfully reproduced, despite a tendency to under-predict (by a few to several times) ice crystal number concentrations and cloud ice mass, in agreement with some other studies. This work serves generally as the basis for improving predictive schemes for cloud ice crystal activation in cloud and climate models, and more specifically as the basis for such a scheme to be used in a Multi-scale Modeling Format (MMF) that utilizes a connected system of cloud-resolving models on a global grid in an effort to better resolve cloud processes and their influence on climate.

Paul J. DeMott, Anthony J. Prenni; Sonia M. Kreidenweis

2012-09-28T23:59:59.000Z

179

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

180

Pacific Northwest Laboratory annual report for 1994 to the DOE Office of Energy Research. Part 2: Atmospheric and climate research  

Science Conference Proceedings (OSTI)

Atmospheric research at Pacific Northwest Laboratory (PNL) occurs in conjunction with the Atmospheric Chemistry Program (ACP) and with the Atmospheric Studies in Complex Terrain (ASCOT) Program. Solicitations for proposals and peer review were used to select research projects for funding in FY 1995. Nearly all ongoing projects were brought to a close in FY 1994. Therefore, the articles in this volume include a summary of the long-term accomplishments as well as the FY 1994 progress made on these projects. The following articles present summaries of the progress in FY 1994 under these research tasks: continental and oceanic fate of pollutants; research aircraft operations; ASCOT program management; coupling/decoupling of synoptic and valley circulations; interactions between surface exchange processes and atmospheric circulations; and direct simulations of atmospheric turbulence. Climate change research at PNL is aimed at reducing uncertainties in the fundamental processes that control climate systems that currently prevent accurate predictions of climate change and its effects. PNL is responsible for coordinating and integrating the field and laboratory measurement programs, modeling studies, and data analysis activities of the Atmospheric Radiation Measurements (ARM) program. In FY 1994, PNL scientists conducted 3 research projects under the ARM program. In the first project, the sensitivity of GCM grid-ad meteorological properties to subgrid-scale variations in surface fluxes and subgrid-scale circulation patterns is being tested in a single column model. In the second project, a new and computationally efficient scheme has been developed for parameterizing stratus cloud microphysics in general circulation models. In the last project, a balloon-borne instrument package is being developed for making research-quality measurements of radiative flux divergence profiles in the lowest 1,500 meters of the Earth`s atmosphere.

NONE

1995-04-01T23:59:59.000Z

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181

Mesoscale Modeling During Mixed-Phase Arctic Cloud Experiment  

SciTech Connect

Mixed-phase arctic stratus clouds are the predominant cloud type in the Arctic (Curry et al. 2000) and through various feedback mechanisms exert a strong influence on the Arctic climate. Perhaps one of the most intriguing of their features is that they tend to have liquid tops that precipitate ice. Despite the fact that this situation is colloidally unstable, these cloud systems are quite long lived - from a few days to over a couple of weeks. It has been hypothesized that mixed-phase clouds are maintained through a balance between liquid water condensation resulting from the cloud-top radiative cooling and ice removal by precipitation (Pinto 1998; Harrington et al. 1999). In their modeling study Harrington et al. (1999) found that the maintenance of this balance depends strongly on the ambient concentration of ice forming nucleus (IFN). In a follow-up study, Jiang et al. (2002), using only 30% of IFN concentration predicted by Meyers et al. (1992) IFN parameterization were able to obtain results similar to the observations reported by Pinto (1998). The IFN concentration measurements collected during the Mixed-Phase Arctic Cloud Experiment (M-PACE), conducted in October 2004 over the North Slope of Alaska and the Beaufort Sea (Verlinde et al. 2005), also showed much lower values then those predicted (Prenne, pers. comm.) by currently accepted ice nucleation parameterizations (e.g. Meyers et al. 1992). The goal of this study is to use the extensive IFN data taken during M-PACE to examine what effects low IFN concentrations have on mesoscale cloud structure and coastal dynamics.

Avramov, A.; Harringston, J.Y.; Verlinde, J.

2005-03-18T23:59:59.000Z

182

Aerosol Impacts on Clouds and Precipitation in Eastern China: Results from Bin and Bulk Microphysics  

Science Conference Proceedings (OSTI)

Using the Weather Research and Forecasting (WRF) model coupled with a 3 spectral-bin microphysics ('SBM') and measurements from the Atmospheric Radiation 4 Measurement (ARM) Mobile Facility field campaign in China (AMF-China), the authors 5 examine aerosol indirect effects (AIE) in the typical cloud regimes of the warm and cold 6 seasons in Southeast China: deep convective clouds (DCC) and stratus clouds (SC), 7 respectively. Comparisons with a two-moment bulk microphysics ('Bulk') are performed 8 to gain insights for improving bulk schemes in estimating AIE in weather and climate 9 simulations. For the first time, measurements of aerosol and cloud properties acquired in 10 China are used to evaluate model simulations to better understand AIE in China. It is 11 found that changes in cloud condensation nuclei (CCN) concentration significantly 12 change the timing of storms, the spatial and temporal distributions of precipitation, the 13 frequency distribution of precipitation rate, as well as cloud base and top heights for the 14 DCC, but not for the SC. CCN increase cloud droplet number (Nc) and mass 15 concentrations, decrease raindrop number concentration (Nr), and delay the onset of 16 precipitation. It is indicated much higher Nc and the opposite CCN effects on convection 17 and heavy rain with Bulk compared to SBM stem from the fixed CCN prescribed in Bulk. 18 CCN have a significant effect on ice microphysical properties with SBM but not Bulk 19 and different condensation/deposition freezing parameterizations employed could be the 20 main reason. This study provided insights to further improve the bulk scheme to better 21 account for aerosol-cloud interactions in regional and global climate simulations, which 22 will be the focus for a follow-on paper.

Fan, Jiwen; Leung, Lai-Yung R.; Li, Zhanqing; Morrison, H.; Chen, Hongbin; Zhou, Yuquan; Qian, Yun; Wang, Yuan

2012-01-19T23:59:59.000Z