NYCCS/ITPA-MSRC Seminar

Marat Khairoutdinov

Department of Atmospheric Science
Colorado State University

“Super-Parametrization – A Direct Use of a Cloud-Resolving Model in Climate Simulation”

Monday, February 12, 2007
Endeavour Hall, Room 120
10:00 AM

Recent advances in computing technology have allowed a new kind of general circulation model (GCM) to emerge, a Multi-scale Modeling Framework (MMF). It is becoming an increasingly practical tool in the area of climate modeling. In MMF, most of conventional sub-GCM-grid-scale parameterizations in each grid-column are replaced with imbedded cloud-resolving model (CRM), which in this context is often called a super-parameterization. The MMF approach allows clouds, aerosols, turbulence, and radiation processes interact on the cloud-scale, as they do in nature. One particular strength of the MMF approach is that it provides a direct link among the GCM, CRM, and cloud microphysics communities.

Recent results of a Cess-type +2K SST climate sensitivity experiment as well as a 19-year long AMIP-style climate simulation will be discussed. The MMF does a good job of reproducing the interannual variability in terms of spatial structure and magnitude of major atmospheric anomalies associated with the ENSO. The subseasonal variability of tropical climate associated with the Maddan-Julian Oscillation (MJO) and equatorially trapped waves are particular strengths of the simulation. The observed seasonal and interannual variations of the strength of the MJO are also well reproduced. Some MMF-specific results will also be shown; for example, the physical realism of the marine stratocumulus clouds as simulated by the MMF. Results of hi-resolution cloud-resolving simulations in the context of cumulus parameterization development will also be briefly discussed.