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Improvements In Representations Of Cloud Microphysics For Bbhrp And Models Using Data Collected During M Pace And Twp Ice
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Book Synopsis Improvements in Representations of Cloud Microphysics for BBHRP and Models Using Data Collected During M-PACE and TWP-ICE. by :
Download or read book Improvements in Representations of Cloud Microphysics for BBHRP and Models Using Data Collected During M-PACE and TWP-ICE. written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In our research we proposed to use data collected during the 2004 Mixed-Phase Arctic Cloud Experiment (MPACE) and the 2006 Tropical Warm Pool International Cloud Experiment (TWP-ICE) to improve retrievals of ice and mixed-phase clouds, to improve our understanding of how cloud and radiative processes affect cloud life cycles, and to develop and test methods for using ARM data more effectively in model. In particular, we proposed to: 1) use MPACE in-situ data to determine how liquid water fraction and cloud ice and liquid effective radius (r{sub ei} and r{sub ew}) vary with temperature, normalized cloud altitude and other variables for Arctic mixed-phase clouds, and to use these data to evaluate the performance of model parameterization schemes and remote sensing retrieval algorithms; 2) calculate rei and size/shape distributions using TWP-ICE in-situ data, investigate their dependence on cirrus type (oceanic or continental anvils or cirrus not directly traced to convection), and develop and test representations for MICROBASE; 3) conduct fundamental research enhancing our understanding of cloud/radiative interactions, concentrating on effects of small crystals and particle shapes and sizes on radiation; and 4) improve representations of microphysical processes for models (fall-out, effective density, mean scattering properties, rei and rew) and provide them to ARM PIs. In the course of our research, we made substantial progress on all four goals.
Book Synopsis Final Report for "Improved Representations of Cloud Microphysics for Model and Remote Sensing Evaluation Using Data Collected During ISDAC, TWP-ICE and RACORO. by :
Download or read book Final Report for "Improved Representations of Cloud Microphysics for Model and Remote Sensing Evaluation Using Data Collected During ISDAC, TWP-ICE and RACORO. written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We were funded by ASR to use data collected during ISDAC and TWP-ICE to evaluate models with a variety of temporal and spatial scales, to evaluate ground-based remote sensing retrievals and to develop cloud parameterizations with the end goal of improving the modeling of cloud processes and properties and their impact on atmospheric radiation. In particular, we proposed to: 1) Calculate distributions of microphysical properties observed in arctic stratus during ISDAC for initializing and evaluating LES and GCMs, and for developing parameterizations of effective particle sizes, mean fall velocities, and mean single-scattering properties for such models; 2) Improve representations of particle sizes, fall velocities and scattering properties for tropical and arctic cirrus using TWP-ICE, ISDAC and M-PACE data, and to determine the contributions that small ice crystals, with maximum dimensions D less than 50 [mu]m, make to mass and radiative properties; 3) Study fundamental interactions between clouds and radiation by improving representations of small quasi-spherical particles and their scattering properties. We were additionally funded 1-year by ASR to use RACORO data to develop an integrated product of cloud microphysical properties. We accomplished all of our goals.
Book Synopsis Analysis of In Situ Observations of Cloud Microphysics from M-PACE Final Report, DOE Grant Agreement No. DE-FG02-06ER64168 by :
Download or read book Analysis of In Situ Observations of Cloud Microphysics from M-PACE Final Report, DOE Grant Agreement No. DE-FG02-06ER64168 written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the findings and accomplishments of work performed under DOE Grant Agreement No. DE-FG02-06ER64168. The focus of the work was the analysis of in situ observations collected by the University of North Dakota Citation research aircraft during the Mixed-Phase Arctic Cloud Experiment (M-PACE). This project was conducted in 2004 along the North Slope of Alaska. The objectives of the research were: to characterize certain microphysical properties of clouds sampled during M-PACE, including spatial variability, precipitation formation, ice multiplication; to examine instrument performance and certain data processing algorithms; and to collaborate with other M-PACE investigators on case study analyses. A summary of the findings of the first two objectives is given here in parts 1 and 2; full results are contained in reports listed in part 3 of this report. The collaborative efforts are described in the publications listed in part 3.
Book Synopsis Testing Cloud Microphysics Parameterizations and Improving the Representation of the Wegner-Bergeron-Findeisen Process in Mixed-phase Clouds in NCAR CAM5 by : Meng Zhang
Download or read book Testing Cloud Microphysics Parameterizations and Improving the Representation of the Wegner-Bergeron-Findeisen Process in Mixed-phase Clouds in NCAR CAM5 written by Meng Zhang and published by . This book was released on 2017 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mixed-phase clouds are persistently observed in the Arctic and the phase partition of cloud liquid and ice in mixed-phase clouds has important impacts on the surface energy budget and Arctic climate. In this study, we test the NCAR Community Atmosphere Model Version 5 (CAM5) in the single-column and weather forecast modes and evaluate the model performance against observation data obtained during the DOE Atmospheric Radiation Measurement (ARM) Program’s M-PACE field campaign in October 2004 and long-term ground-based multi-sensor measurements. We find that CAM5, like other global climate models, poorly simulates the phase partition in mixed-phase clouds by significantly underestimating the cloud liquid water content. An assumption of the pocket structure in the distribution of cloud liquid and ice based on in situ observations inside mixed-phase clouds has provided a possible solution to improve the model performance by reducing the Wegner-Bergeron-Findeisen (WBF) process rate. In this study, the modification of the WBF process in the CAM5 model has been achieved with applying a stochastic perturbation to the time scale of the WBF process relevant to both ice and snow to account for the heterogeneous mixture of cloud liquid and ice. Our results show that the modification of the WBF process improves the modeled phase partition in mixed-phase clouds. The seasonality of mixed-phase cloud properties is also better captured in the model compared with long-term ground-based remote sensing observations. Furthermore, the phase partitioning is insensitive to the reassignment time step of perturbations.
Book Synopsis Determining Best Estimates and Uncertainties in Cloud Microphysical Parameters from ARM Field Data by :
Download or read book Determining Best Estimates and Uncertainties in Cloud Microphysical Parameters from ARM Field Data written by and published by . This book was released on 2015 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: We proposed to analyze in-situ cloud data collected during ARM/ASR field campaigns to create databases of cloud microphysical properties and their uncertainties as needed for the development of improved cloud parameterizations for models and remote sensing retrievals, and for evaluation of model simulations and retrievals. In particular, we proposed to analyze data collected over the Southern Great Plains (SGP) during the Mid-latitude Continental Convective Clouds Experiment (MC3E), the Storm Peak Laboratory Cloud Property Validation Experiment (STORMVEX), the Small Particles in Cirrus (SPARTICUS) Experiment and the Routine AAF Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations (RACORO) field campaign, over the North Slope of Alaska during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) and the Mixed-Phase Arctic Cloud Experiment (M-PACE), and over the Tropical Western Pacific (TWP) during The Tropical Warm Pool International Cloud Experiment (TWP-ICE), to meet the following 3 objectives; derive statistical databases of single ice particle properties (aspect ratio AR, dominant habit, mass, projected area) and distributions of ice crystals (size distributions SDs, mass-dimension m-D, area-dimension A-D relations, mass-weighted fall speeds, single-scattering properties, total concentrations N, ice mass contents IWC), complete with uncertainty estimates; assess processes by which aerosols modulate cloud properties in arctic stratus and mid-latitude cumuli, and quantify aerosol's influence in context of varying meteorological and surface conditions; and determine how ice cloud microphysical, single-scattering and fall-out properties and contributions of small ice crystals to such properties vary according to location, environment, surface, meteorological and aerosol conditions, and develop parameterizations of such effects. In this report we describe the accomplishments that we made on all 3 research objectives.
Book Synopsis Evaluation of Mixed-Phase Cloud Microphysics Parameterizations with the NCAR Single Column Climate Model (SCAM) and ARM Observations by :
Download or read book Evaluation of Mixed-Phase Cloud Microphysics Parameterizations with the NCAR Single Column Climate Model (SCAM) and ARM Observations written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis Simulating Mixed-phase Arctic Stratus Clouds by :
Download or read book Simulating Mixed-phase Arctic Stratus Clouds written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis Evaluation of A New Mixed-Phase Cloud Microphysics Parameterization with the NCAR Climate Atmospheric Model (CAM3) and ARM Observations Fourth Quarter 2007 ARM Metric Report by :
Download or read book Evaluation of A New Mixed-Phase Cloud Microphysics Parameterization with the NCAR Climate Atmospheric Model (CAM3) and ARM Observations Fourth Quarter 2007 ARM Metric Report written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Mixed-phase clouds are composed of a mixture of cloud droplets and ice crystals. The cloud microphysics in mixed-phase clouds can significantly impact cloud optical depth, cloud radiative forcing, and cloud coverage. However, the treatment of mixed-phase clouds in most current climate models is crude and the partitioning of condensed water into liquid droplets and ice crystals is prescribed as temperature dependent functions. In our previous 2007 ARM metric reports a new mixed-phase cloud microphysics parameterization (for ice nucleation and water vapor deposition) was documented and implemented in the NCAR Community Atmospheric Model Version 3 (CAM3). The new scheme was tested against the Atmospheric Radiation Measurement (ARM) Mixed-phase Arctic Cloud Experiment (M-PACE) observations using the single column modeling and short-range weather forecast approaches. In this report this new parameterization is further tested with CAM3 in its climate simulations. It is shown that the predicted ice water content from CAM3 with the new parameterization is in better agreement with the ARM measurements at the Southern Great Plain (SGP) site for the mixed-phase clouds.
Book Synopsis Simulating Mixed-phase Arctic Stratus Clouds by :
Download or read book Simulating Mixed-phase Arctic Stratus Clouds written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis Retrieval of Cloud Phase Using the Moderate Resolution Imaging Spectroradiometer Data During the Mixed-Phase Arctic Cloud Experiment by :
Download or read book Retrieval of Cloud Phase Using the Moderate Resolution Imaging Spectroradiometer Data During the Mixed-Phase Arctic Cloud Experiment written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Improving climate model predictions over Earth's polar regions requires a comprehensive knowledge of polar cloud microphysics. Over the Arctic, there is minimal contrast between the clouds and background snow surface, making it difficult to detect clouds and retrieve their phase from space. Snow and ice cover, temperature inversions, and the predominance of mixed-phase clouds make it even more difficult to determine cloud phase. Also, since determining cloud phase is the first step toward analyzing cloud optical depth, particle size, and water content, it is vital that the phase be correct in order to obtain accurate microphysical and bulk properties. Changes in these cloud properties will, in turn, affect the Arctic climate since clouds are expected to play a critical role in the sea ice albedo feedback. In this paper, the IR trispectral technique (IRTST) is used as a starting point for a WV and 11-[micro]m brightness temperature (T11) parameterization (WVT11P) of cloud phase using MODIS data. In addition to its ability to detect mixed-phase clouds, the WVT11P also has the capability to identify thin cirrus clouds overlying mixed or liquid phase clouds (multiphase ice). Results from the Atmospheric Radiation Measurement (ARM) MODIS phase model (AMPHM) are compared to the surface-based cloud phase retrievals over the ARM North Slope of Alaska (NSA) Barrow site and to in-situ data taken from University of North Dakota Citation (CIT) aircraft which flew during the Mixed-Phase Arctic Cloud Experiment (MPACE). It will be shown that the IRTST and WVT11P combined to form the AMPHM can achieve a relative high accuracy of phase discrimination compared to the surface-based retrievals. Since it only uses MODIS WV and IR channels, the AMPHM is robust in the sense that it can be applied to daytime, twilight, and nighttime scenes with no discontinuities in the output phase.
Book Synopsis Final Report on the Development of an Improved Cloud Microphysical Product for Model and Remote Sensing Evaluation Using RACORO Observations by :
Download or read book Final Report on the Development of an Improved Cloud Microphysical Product for Model and Remote Sensing Evaluation Using RACORO Observations written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We proposed to analyze data collected during the Routine Aerial Facilities (AAF) Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations (RACORO) in order to develop an integrated product of cloud microphysical properties (number concentration of drops in different size bins, total liquid drop concentration integrated over all bin sizes, liquid water content LWC, extinction of liquid clouds bw, effective radius of water drops re, and radar reflectivity factor) that could be used to evaluate large-eddy simulations (LES), general circulation models (GCMs) and ground-based remote sensing retrievals, and to develop cloud parameterizations with the end goal of improving the modeling of cloud processes and properties and their impact on atmospheric radiation. We have completed the development of this microphysical database and have submitted it to ARM for consideration of its inclusion on the ARM database as a PI product. This report describes the development of this database, and also describes research that has been conducted on cloud-aerosol interactions using the data obtained during RACORO. A list of conference proceedings and publications is also included.
Book Synopsis Mixed-phase Cloud Microphysics Over Mountainous Terrain Emphasizing Airborne Dual-wavelength Retrieval Approach by : Coltin Dale Grasmick
Download or read book Mixed-phase Cloud Microphysics Over Mountainous Terrain Emphasizing Airborne Dual-wavelength Retrieval Approach written by Coltin Dale Grasmick and published by . This book was released on 2021 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: Kelvin-Helmholtz (KH) waves are common in deep stratiform precipitation systems associated with frontal disturbances, especially in the vicinity of complex terrain, as is evident from transects of vertical velocity and 2D circulation, obtained from a 3-mm airborne Doppler radar, the Wyoming Cloud Radar. These waves are observed in a variety of wavelengths, depths, amplitudes, and turbulence intensities. Complex terrain may locally enhance wind shear which reduces the Richardson number and leads to KH instability. KH waves are frequently locked to the terrain, and occur at various heights, including within the free troposphere, at the boundary layer top, and close to the surface. They are observed not only upwind of terrain barriers, as has been documented before, but also in the wake of steep terrain, where the waves can be highly turbulent. KH waves are a source of turbulence in stratiform precipitation systems over mountainous terrain. They introduce large eddies into otherwise laminar flow, with updrafts and downdrafts breaking down into small-scale turbulence. When they occur in-cloud, such dynamics influence microphysical processes that impact precipitation growth and fallout. Measurements within KH wave updrafts reveal the production of liquid water in otherwise ice-dominated clouds, which can contribute to snow generation or enhancement via depositional and accretional growth. Fallstreaks beneath KH waves contain higher ice water content, composed of larger and more numerous ice particles, suggesting that KH waves and associated turbulence may also increase ice nucleation. A Large-Eddy Simulation (LES), designed to model the microphysical response to the KH wave eddies in mixed phase cloud, shows that depositional and accretional growth can be enhanced in KH waves, resulting in more precipitation when compared to a baseline simulation.Properties of frozen hydrometeors in clouds remain difficult to remotely sense. Estimates of number concentration, distribution shape, ice particle density, and ice water content are essential for connecting cloud processes to surface precipitation. Researching the microphysical effects of dynamic features like KH waves heavily relies on in situ measurements on an aircraft or at the surface but these observations substantially under-sample the cloud and miss the effects of the KH waves. Progress has been made with dual-frequency radars, but validation has been difficult because of a lack of cloud microphysical observations collocated with the radar measurements Here, data are used from two airborne profiling (up & down) radars, the W-band Wyoming Cloud Radar and the Ka-band Profiling Radar, allowing for Ka-W-band Dual-Wavelength Ratio (DWR) profiles. The aircraft (the University of Wyoming King Air) also carried a suite of in situ cloud and precipitation probes. This arrangement is optimal for relating the “flight-level” DWR (an average from radar gates below and above flight level) to ice particle size distributions measured by in situ optical array probes, as well as bulk properties such as minimum snow particle density and ice water content. This comparison reveals a strong relationship between DWR and the ice particle median volume diameter. The DWR-defined size distribution shape is used with a Mie scattering model and an experimental mass-diameter relationship to estimate ice particle concentration and ice water content. Comparison with flight-level cloud-probe data indicate good performance, allowing microphysical interpretations for vertical radar transects.
Book Synopsis Development and Testing of Parameterizations for Continental and Tropical Ice Cloud Microphysical and Radiative Properties in GCM and Mesoscale Models. Final Report by :
Download or read book Development and Testing of Parameterizations for Continental and Tropical Ice Cloud Microphysical and Radiative Properties in GCM and Mesoscale Models. Final Report written by and published by . This book was released on 1997 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall purpose of this research was to exploit measurements in clouds sampled during several field programs, especially from experiments in tropical regions, in a four-component study to develop and validate cloud parameterizations for general circulation models, emphasizing ice clouds. The components were: (1) parameterization of basic properties of mid- and upper-tropospheric clouds, such as condensed water content, primarily with respect to cirrus from tropical areas; (2) the second component was to develop parameterizations which express cloud radiative properties in terms of basic cloud microphysical properties, dealing primarily with tropical oceanic cirrus clouds and continental thunderstorm anvils, but also including altocumulus clouds; (3) the third component was to validate the parameterizations through use of ground-based measurements calibrated using existing and planned in-situ measurements of cloud microphysical properties and bulk radiative properties, as well as time-resolved data collected over extended periods of time; (4) the fourth component was to implement the parameterizations in the National Center for Atmospheric Research (NCAR) community climate model (CCM) II or in the NOAA-GFDL model (by L. Donner GFDL) and to perform sensitivity studies.
Download or read book Programme written by and published by . This book was released on 1911* with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Microphysics of Ice Clouds by : Rosemary M. Dyer
Download or read book The Microphysics of Ice Clouds written by Rosemary M. Dyer and published by . This book was released on 1979 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published results of observations of crystal habits, particle sizes and numbers of ice particles in clouds are summarized and discussed. There are systematic variations with cloud type, and in some instances, with cloud age and location within a cloud system. However, the body of data available is insufficient to formulate a climatology of ice cloud microphysics. The several measurement techniques in current use are evaluated, as are some of the techniques now under consideration for future use. The particle enhancement observed on some occasions is discussed, and the various theories accounting for it presented. Finally, recommendations are made concerning future field programs and theoretical studies required before accurate predictions of the ice cloud microphysical environment can be made. (Author)
Book Synopsis A Comparison of Cloud Microphysical Quantities with Forecasts from Cloud Prediction Models by :
Download or read book A Comparison of Cloud Microphysical Quantities with Forecasts from Cloud Prediction Models written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical weather prediction models (ECMWF, NCEP) are evaluated using ARM observational data collected at the Southern Great Plains (SGP) site. Cloud forecasts generated by the models are compared with cloud microphysical quantities, retrieved using a variety of parameterizations. Information gained from this comparison will be utilized during the FASTER project, as models are evaluated for their ability to reproduce fast physical processes detected in the observations. Here the model performance is quantified against the observations through a statistical analysis. Observations from remote sensing instruments (radar, lidar, radiometer and radiosonde) are used to derive the cloud microphysical quantities: ice water content, liquid water content, ice effective radius and liquid effective radius. Unfortunately, discrepancies in the derived quantities arise when different retrieval schemes are applied to the observations. The uncertainty inherent in retrieving the microphysical quantities using various retrievals is estimated from the range of output microphysical values. ARM microphysical retrieval schemes (Microbase, Mace) are examined along with the CloudNet retrieval processing of data from the ARM sites for this purpose. Through the interfacing of CloudNet and "ARM" processing schemes an ARMNET product is produced and employed as accepted observations in the assessment of cloud model predictions.
Book Synopsis Final Report Fir DE-SC0005507 (A1618) by :
Download or read book Final Report Fir DE-SC0005507 (A1618) written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We proposed to analyze data collected during the Routine Aerial Facilities (AAF) Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations (RACORO) in order to develop an integrated product of cloud microphysical properties (number concentration of drops in different size bins, total liquid drop concentration integrated over all bin sizes, liquid water content LWC, extinction of liquid clouds, effective radius of water drops, and radar reflectivity factor) that could be used to evaluate large-eddy simulations (LES), general circulation models (GCMs) and ground-based remote sensing retrievals, and to develop cloud parameterizations with the end goal of improving the modeling of cloud processes and properties and their impact on atmospheric radiation. We have completed the development of this microphysical database. we investigated the differences in the size distributions measured by the Cloud and Aerosol Spectrometer (CAS) and the Forward Scattering Probe (FSSP), between the one dimensional cloud imaging probe (1DC) and the two-dimensional cloud imaging probe (2DC), and between the bulk LWCs measured by the Gerber probe against those derived from the size resolved probes.
