Diagnostic study of improved simulation of low-level clouds with ACME candidate convective scheme
Authors
Wuyin Lin — Brookhaven National Laboratory
Shaocheng Xie — Lawrence Livermore National Laboratory
Andrew M. Vogelmann — Brookhaven National Laboratory
Hsi-Yen Ma — Lawrence Livermore National Laboratory
Vincent Larson — University of Wisconsin, Milwaukee
Category
Warm low clouds, including aerosol interactions
Description
Simulations of low-level clouds are markedly improved with candidate convective scheme for the Accelerated Climate Modeling for Energy (ACME) atmosphere model. The candidate scheme are Cloud Layers Unified By Binormals (CLUBB) scheme for boundary-layer turbulence, shallow convection and cloud macrophysics, and Unified Convection (UNICON) scheme for both shallow and deep convections. Significant improvements can be seen, for instance, in cloud regime transition along the GPCI* cross-section and in temporal variations over the ARM Southern Great Plains (SGP) site. Same improvements can be observed in long-term AMIP-type of simulations and short-term hindcasts. This work presents a diagnostic study of the boundary layer and cloud processes leading to the improved low-level cloud simulations, using hindcasts based on the Cloud-Associated Parameterization Testbed (CAPT) framework. The Routine ARM Aerial Facility CLOWD** Optical Radiative Observations (RACORO) campaign over the SGP is used as a case study for detailed process-level analysis.
*Note:
GPCI = GCSS Pacific Cross-section Intercomparison, a working group of GCSS
GCSS = GEWEX Cloud Systems Study
GEWEX = Global Energy and Water Cycle Experiment, a core project of the World Climate Research Programme
**Note:
CLOWD = Clouds with Low Optical Water Depths