Three Dimensional Modeling of Dynamical Interactions With Convective, Radiative, and Surface Fluxes Over the Tropical Pacific

Abstract ATM-9319461 Seager, R. Zebiak, Stephen E. Columbia University Title: Three Dimensional Modeling of Dynamical Interactions with Convective, Radiative and Surface Fluxes Over the Tropical Pacific This project will concern the interaction between the convective, radiative and surface fluxes over the Pacific sector with an emphasis on the west Pacific. The PIs will use a newly developed, efficient and accurate, global, linear primitive equation model together with parameterizations of moist convection, radiative transfer and boundary layer processes. The ultimate goal of the work is to improve model representation of these processes in order to improve model simulations of the large scale variables (especially near surface properties) necessary for continued progress in simulation and prediction of climate variability on time scales of months to decades. Verification of model physics will hence be based on observations of these processes within the TOGA COARE domain and also on their effect on simulation of the large scale circulation. The PIs are especially interested in being able to model the observed limited scale of convection and convective anomalies, errors in which currently create large errors in modelled surface winds. This work will proceed through experiments with observed SST forcing and through studies of the role of the radiative, convection and surface fluxes in determination of the character and organization of propagating convective disturbances. Another focus of the work will be on the surface energy budget of the west Pacific. The PIs will aim to reconcile estimates of the flux, and its components, derived from the atmospheric modeling work with other estimates derived from ocean SST modeling and with the TOGA COARE data. The various roles of convection, radiation and boundary layer processes in determining the surface flux will be analyzed. This research is important because it seeks to clarify proces ses important for understanding climate variability. It is funded under the TOGA COARE program.