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Dynamical controls on sub–global climate model grid‐scale cloud variability for Atmospheric Radiation Measurement Program (ARM) case 4

Journal Article · · Journal of Geophysical Research
 [1];  [2];  [2];  [3]
  1. Center for Environmental Prediction and Department of Environmental Sciences Rutgers–State University of New Jersey New Brunswick New Jersey USA; Scripps Institution of Oceanography/UCSD
  2. Scripps Institution of Oceanography University of California San Diego, La Jolla California USA
  3. Atmospheric Science Division Lawrence Livermore National Laboratory Livermore California USA
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Global climate models (GCMs) produce large errors in cloudiness and cloud radiative forcing when simulating midlatitude, synoptic-scale cloud systems. This is because they do not represent the subgrid-scale processes in these systems that create subgrid variability in cloud optical thickness and cloud top pressure. Improving GCM performance will require a better understanding of these controls on subgrid cloud variability. To begin addressing this issue, this paper uses a mesoscale model, the Regional Atmospheric Modeling System (RAMS), to simulate two case study synoptic storms with much higher resolution than is possible in a GCM. These storms were observed during the Atmospheric Radiation Measurement (ARM) Program's March 2000 Intensive Observing Period (IOP) in the U.S. southern Great Plains (SGP), otherwise knows as ARM case 4. We find that RAMS is able to capture the observed storm morphology, lifecycle, and vertical structure of the atmospheric dynamic and thermodynamic variables. RAMS is also able to capture the observed fine-scale vertical structure and temporal variation of the cloud field. Given this agreement with observations, we then characterize the model-simulated variability in cloudiness and other variables such as vertical velocity. In both storms, there is a high degree of spatial and temporal variability in the vertical motion field across multiple scales. The variability in above-boundary layer cloudiness is closely linked to this dynamical variability. This suggests that a parameterization for subgrid cloud water based on subgrid vertical velocity could be used to improve GCM simulations of midlatitude clouds.

Research Organization:
Scripps Research Institute, San Diego, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Biological and Environmental Research (BER)
DOE Contract Number:
FG02-02ER63332
OSTI ID:
876553
Report Number(s):
DOE/ER/63332-3
Journal Information:
Journal of Geophysical Research, Journal Name: Journal of Geophysical Research Journal Issue: D15 Vol. 110; ISSN 0148-0227
Publisher:
American Geophysical Union
Country of Publication:
United States
Language:
English

References (33)

New RAMS cloud microphysics parameterization part I: the single-moment scheme journal September 1995
RAMS 2001: Current status and future directions journal January 2003
Cloud and Radiation Variations Associated with Northern Midlatitude Low and High Sea Level Pressure Regimes journal January 2000
Unresolved spatial variability and microphysical process rates in large-scale models journal November 2000
Development of a turbulence closure model for geophysical fluid problems journal January 1982
Impact of temperature and humidity variability on cloud cover assessed using aircraft data journal July 2003
A lateral boundary formulation for multi-level prediction models: PREDICTION MODELS journal April 1976
The Atmospheric Radiation Measurement Program Cloud Radars: Operational Modes journal July 1999
Improved Techniques for Evaluating GCM Cloudiness Applied to the NCAR CCM3 journal June 2001
Midlatitude Frontal Clouds: GCM-Scale Modeling Implications journal August 2000
Seasonal variation of cloud radiative forcing derived from the Earth Radiation Budget Experiment journal January 1990
A Prognostic Parameterization for the Subgrid-Scale Variability of Water Vapor and Clouds in Large-Scale Models and Its Use to Diagnose Cloud Cover journal June 2002
Simulations of a Cold Front by Cloud-Resolving, Limited-Area, and Large-Scale Models, and a Model Evaluation Using In Situ and Satellite Observations journal September 2000
A preferred scale for landscape forced mesoscale circulations? journal November 2003
A scheme for predicting layer clouds and their water content in a general circulation model journal January 1990
The role of the convective ?trigger function? in numerical forecasts of mesoscale convective systems journal January 1992
Relationships between Large-Scale Vertical Velocity, Static Stability, and Cloud Radiative Forcing over Northern Hemisphere Extratropical Oceans* journal November 1997
Subgrid-Scale Condensation in Models of Nonprecipitating Clouds journal February 1977
The NCEP/NCAR 40-Year Reanalysis Project journal March 1996
Objective Determination of Cloud Heights and Radar Reflectivities Using a Combination of Active Remote Sensors at the ARM CART Sites journal May 2000
Coarse-Grid and Cloud-Resolving Simulations of a Midlatitude Cyclonic Cloud System: Implications for the Parameterization of Layer Clouds in GCMs journal June 2000
Efficiency of storm tracks an important climate parameter? The role of cloud radiative forcing in poleward heat transport journal January 2003
Coupled Atmosphere–Biophysics–Hydrology Models for Environmental Modeling journal June 2000
Confronting Models with Data: The GEWEX Cloud Systems Study: The GEWEX Cloud Systems Study journal April 2003
Cloud feedback in atmospheric general circulation models: An update journal May 1996
Evaluation of midlatitude cloud properties in a weather and a climate model: Dependence on dynamic regime and spatial resolution journal January 2002
Validation and Sensitivities of Frontal Clouds Simulated by the ECMWF Model journal October 1999
Objective Analysis of ARM IOP Data: Method and Sensitivity journal February 2001
An Improved Strategy for the Evaluation of Cloud Parameterizations in GCMS journal October 2003
Cluster analysis of cloud regimes and characteristic dynamics of midlatitude synoptic systems in observations and a model journal January 2005
New RAMS cloud microphysics parameterization. Part II: The two-moment scheme journal August 1997
Evaluation of the Vertical Structure of Zonally Averaged Cloudiness and Its Variability in the Atmospheric Model Intercomparison Project journal December 1996
Simulations of midlatitude frontal clouds by single-column and cloud-resolving models during the Atmospheric Radiation Measurement March 2000 cloud intensive operational period journal January 2005

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