The representation of air-sea fluxes in cold air outbreaks in satellite and MERRA data

The occurrence of cold air outbreaks over the Gulf of Mexico are the cause of much of the severe weather during the winter months in the Southeast, and the air mass modification and return flow characteristics are still not well forecasted. The amount of in situ observations of the air-sea flux state before, during, and after a cold air outbreak is limited, and observations from experiments have occurred only in the western part of the basin during GUFMEX. Given the difference in the ocean conditions between the western and the eastern part of the basin due to the Loop Current, it is to be anticipated that there would be differences in the air-sea interaction across the Gulf.

In this talk we will present the results of an analysis of more than 25 years of MERRA data to provide a climatology of the of cold air outbreaks over the Gulf of Mexico. It will be shown that cold air outbreaks provide the significant source of heat loss in all parts of the basin during the winter months, and that there are differences in the number, length, and strength of the outbreaks between the western and eastern basin. We will compare the MERRA results with the SeaFlux satellite turbulent flux dataset as well as the radiative fluxes from ISCCP. Comparisons with buoys will provide error estimates and an analysis of differences between the model simulations and the satellite fluxes will be discussed.