A5054074227- Meteorological Phenomena and Simulations
- Climate variability and models
- Atmospheric aerosols and clouds
- Atmospheric chemistry and aerosols
- Atmospheric and Environmental Gas Dynamics
- Wind and Air Flow Studies
- Tropical and Extratropical Cyclones Research
- Atmospheric Ozone and Climate
- Fluid Dynamics and Turbulent Flows
- Solar Radiation and Photovoltaics
- Plant Water Relations and Carbon Dynamics
- Arctic and Antarctic ice dynamics
- Cryospheric studies and observations
- Climate Change Policy and Economics
- Advanced Fiber Optic Sensors
- Integrated Energy Systems Optimization
- Optical Systems and Laser Technology
- Aeolian processes and effects
- Water-Energy-Food Nexus Studies
- Air Quality Monitoring and Forecasting
- Economic and Technological Systems Analysis
- Microbial Community Ecology and Physiology
- Marine and coastal ecosystems
- Ocean Waves and Remote Sensing
- Geophysics and Gravity Measurements
National Oceanic and Atmospheric Administration
2016-2023
Langley Research Center
2005-2022
NOAA National Centers for Environmental Prediction
2017-2020
NOAA Environmental Modeling Center
2017-2020
National Aeronautics and Space Administration
2018
Science Systems and Applications (United States)
2009-2016
Support Systems Associates (United States)
2010-2012
Analytical Services & Materials (United States)
2006-2009
Hampton University
2004-2006
Max Planck Institute for Meteorology
2005
Data from the undisturbed period of Rain in Cumulus over Ocean (RICO) field study are used to create a test case for large-eddy simulations shallow, precipitating, trade-wind cumulus.Measurements upon which based augmented by regional scale downscaling meteorological analyses so as provide forcing data consistent with measurements.Twelve simulations, wide range microphysical representations, compared each other, and independent measurements during RICO.The ensemble average plausibly...
Abstract This paper investigates daytime convective development over land and its representation in single‐column models (SCMs) cloud‐resolving (CRMs). A model intercomparison case is developed based on observations of the diurnal cycle convection during rainy season Amazonia. The focus 6 h period between sunrise early afternoon which was identified previous studies as critical for summertime continents numerical weather prediction climate models. characterized by formation growth a...
We present the main results from second model intercomparison within GEWEX (Global Energy and Water cycle EXperiment) Atmospheric Boundary Layer Study (GABLS). The target is to examine diurnal over land in today's numerical weather prediction climate models for operational research purposes. set-up of case based on observations taken during Cooperative Atmosphere-Surface Exchange Study-1999 (CASES-99), which was held Kansas, USA early autumn with a strong no clouds present. are forced...
Subtropical marine low cloud sensitivity to an idealized climate change is compared in six large‐eddy simulation (LES) models as part of CGILS. July cover simulated at three locations over the subtropical northeast Pacific Ocean, which are typified by cold sea surface temperatures (SSTs) under well‐mixed stratocumulus, cool SSTs decoupled and shallow cumulus clouds overlying warmer SSTs. The includes a uniform 2 K SST increase with corresponding moist‐adiabatic warming aloft subsidence...
Abstract Large‐eddy simulations of mixed‐phase Arctic clouds by 11 different models are analyzed with the goal improving understanding and model representation processes controlling evolution these clouds. In a case based on observations from Indirect Semi‐Direct Aerosol Campaign (ISDAC), it is found that ice number concentration, N i , exerts significant influence cloud structure. Increasing leads to substantial reduction in liquid water path (LWP), agreement earlier studies. contrast...
CGILS—the CFMIP‐GASS Intercomparison of Large Eddy Models (LESs) and single column models (SCMs)—investigates the mechanisms cloud feedback in SCMs LESs under idealized climate change perturbation. This paper describes CGILS results from 15 8 LES models. Three regimes over subtropical oceans are studied: shallow cumulus, cumulus stratocumulus, well‐mixed coastal stratus/stratocumulus. In stratocumulus stratus regimes, without activated convection generally simulated negative feedbacks, while...
We introduce the Clouds Above United States and Errors at Surface (CAUSES) project with its aim of better understanding physical processes leading to warm screen temperature biases over American Midwest in many numerical models. In this first four companion papers, 11 different models, from nine institutes, perform a series 5 day hindcasts, each initialized reanalyses. After describing common experimental protocol detailing model configuration, gridded data set is derived observations used...
Abstract As part of an international intercomparison project, a set single‐column models (SCMs) and cloud‐resolving (CRMs) are run under the weak‐temperature gradient (WTG) method damped gravity wave (DGW) method. For each model, implementation WTG or DGW involves simulated column which is coupled to reference state defined with profiles obtained from same model in radiative‐convective equilibrium. The has surface conditions as initialized state. We performed systematic comparison behavior...
Abstract Satellite based top-of-atmosphere (TOA) and surface radiation budget observations are combined with mass corrected vertically integrated atmospheric energy divergence tendency from reanalysis to infer the regional distribution of TOA, terms over globe. Hemispheric contrasts in used determine radiative sensible latent heat contributions cross-equatorial transports atmosphere (AHT EQ ) ocean (OHT ). The contrast net implies an AHT northern hemisphere (NH) southern (SH) (0.75 PW),...
Abstract Results are presented of the GASS/EUCLIPSE single‐column model intercomparison study on subtropical marine low‐level cloud transition. A central goal is to establish performance state‐of‐the‐art boundary‐layer schemes for weather and climate models this regime, using large‐eddy simulations same scenes as a reference. novelty that comparison covers four different cases instead one, in order broaden covered parameter space. Three situated North‐Eastern Pacific, while one reflects...
Abstract Ten single-column models (SCMs) from eight groups are used to simulate a nocturnal nonprecipitating marine stratocumulus-topped mixed layer as part of an intercomparison organized by the Global Energy and Water Cycle Experiment Cloud System Study, Working Group 1. The case is idealized observations Dynamics Chemistry Marine Stratocumulus II, Research Flight SCM simulations with operational resolution supplemented high-resolution compared large-eddy simulations. All participating...
Abstract The abilities of a cloud‐resolving model (CRM) with double‐Gaussian based and quasi‐Gaussian third‐order closures (TOCs) to simulate shallow cumuli their transition deep convective clouds are compared in this study. TOC is fully prognostic (FP), while the intermediately (IP). latter only predicts three important moments former all moments. A cumulus case simulated by single‐column versions FP IP models large‐eddy simulation (LES). improves greatly over producing more realistic cloud...
Seven boundary‐layer cloud cases are simulated with UCLA‐LES (The University of California, Los Angeles – large eddy simulation) model different horizontal and vertical gridspacing to investigate how the results depend on gridspacing. Some variables more sensitive gridspacing, while others still both gridspacings similar or opposite trends. For cloud‐related having dependence gridspacings, changing proportionally in directions gives appearance convergence. In this study, we mainly discuss...
Abstract The mean structure and diurnal cycle of southeast (SE) Atlantic boundary layer clouds are described with satellite observations multiscale modeling framework (MMF) simulations during austral spring (September–November). Hourly resolution cloud fraction (CF) cloud-top height (HT) retrieved from Meteosat-9 radiances using modified Clouds the Earth’s Radiant Energy System (CERES) Moderate Resolution Imaging Spectroradiometer (MODIS) algorithms, whereas liquid water path (LWP) is...
The process of retrieving cloud optical thickness and effective radius from radiances measured by satellite instruments is simulated to determine the error in both retrieved properties irradiances computed with them. at 0.64 μm 3.7 are for three fields (stratus, stratocumulus, cumulus) generated large eddy simulation models. When overcast pixels assumed horizontal flux neglected retrieval process, domain‐averaged nadir 1% −32% (1% −27%) 0% 67% (0% 63%) solar zenith angle 30° (50°). Using...
[1] In the original multiscale modeling framework (MMF), Community Atmosphere Model (CAM3.5) is used as host general circulation model (GCM), and System for Atmospheric Modeling with a first-order turbulence closure cloud resolving (CRM) representing physical processes in each grid column of GCM. This study introduces an upgrade MMF which scheme replaced by advanced third-order its CRM component. The results are compared between upgraded MMFs, CAM3.5, observations. global distributions...
Abstract In this study, a simplified intermediately prognostic higher-order turbulence closure (IPHOC) is implemented in the Community Atmosphere Model, version 5 (CAM5), to provide consistent treatment of subgrid-scale cloud processes, except for deep convection. The planetary boundary layer (PBL) height prognosticated better resolve discontinuity temperature and moisture above PBL top. Single-column model tests show that fluxes liquid water potential total water, fraction, content are...
The effects of subgrid-scale (SGS) condensation and transport become more important as the grid spacings increase from those typically used in large-eddy simulation (LES) to cloud-resolving models (CRMs). Incorporation these SGS can be achieved by a joint probability density function approach that utilizes higher-order moments thermodynamic dynamic variables. This study examines how well shallow cumulus stratocumulus clouds are simulated two versions CRM implemented with low-order...
Abstract The multiscale modeling framework, which replaces traditional cloud parameterizations with a 2D cloud-resolving model (CRM) in each atmospheric column, is promising approach to climate modeling. CRM component contains an advanced third-order turbulence closure, helping it better simulate low-level clouds. In this study, two simulations are performed 1.9° × 2.5° grid spacing but they differ the vertical resolution. number of layers below 700 hPa increases from 6 one simulation...
Abstract Phase 1 of the CGILS large‐eddy simulation (LES) intercomparison is extended to understand if subtropical marine boundary‐layer clouds respond idealized climate perturbations consistently in six LES models. Here responses quadrupled carbon dioxide ( “ fast adjustment ” ) and a composite perturbation representative CMIP3 multimodel mean 2×CO 2 near‐equilibrium conditions are analyzed. As 1, run equilibrium using specified steady summertime forcings three locations Northeast Pacific...
Abstract Formulating the contribution of subgrid-scale (SGS) variability to microphysical processes in boundary layer and deep convective cloud parameterizations is a challenging task because complexity lack information. In this study, warm-rain microphysics parameterization that based on joint double-Gaussian distribution vertical velocity, liquid water potential temperature, total mixing ratio, perturbation rainwater ratio developed simulate drizzling clouds with single column model (SCM)....
Abstract The eastern Pacific is a climatologically important region. Conventional coupled atmosphere–ocean general circulation models produce positive sea surface temperature biases of 2–5 K in this region because insufficient stratocumulus clouds. In study, global multiscale modeling framework (MMF), which replaces traditional cloud parameterizations with 2D cloud-resolving model (CRM) each atmospheric column, used to examine the seasonal variations CRM component contains an advanced...