ABSTRACT ATM 9319483 Gautier, Catherine University of California, Santa Cruz Title: Relationship between Clouds, SST and Surface Fluxes on Seasonal and Interannual Time Scales Over the Western Pacific The goal of this proposal is to contribute to the clarification of the role of clouds on the surface radiation and latent heat flux in the western Pacific over climatologically significant space and time scales. The data available until recently have not allowed us to estimate unambiguously the magnitude and variability of the dominant mechanisms at work in air-sea interactions in the tropical regions. There are, for instance, competing theories regarding the mechanism responsible for the maintenance of tropical sea surface temperatures at their observed temperature in the western Pacific. Our proposal has three objectives. First, we will compute cloud and surface (shortwave radiation and latent heat) fluxes from satellite observations using techniques we have developed or adapted from other investigators. Second, we will intercompare our satellite results with surface and aircraft observations to ensure the quality of the satellite-derived surface fluxes. Third, and this is the heart of oup proposal, we will investigate the effect of clouds on surface fluxes (including SST) over climatologically significant space and time scales. Our approach uses satellite data extensively to provide the large scale framework, and it also builds upon the availability of TOGA- COARE data to validate our satellite data and perform some process- oriented studies. The investigation will, however, extend the results from the TOGA-COARE IOP to longer time periods in order to explore seasonal and interannual variability. Results from this research are expected to lead to a better understanding of some of the mechanisms controlling air-sea interactions and, thus, should help in the development of new parameterizations for a hierarchy of numerical models aimed at simulating the coupled atmosphere-ocean system over seasonal to interannual time scales in the tropical regions.
