A Study of Ocean-atmospheric Interactions over the Gulf of Mexico during Non Cyclonic and Cyclonic Activity

Under the NASA-FAR Program, a study has been established to investigate Oecean-Atmospheric interactions and their relation in the formation and development of tropical cyclone/hurricane over the Gulf of Mexico. A comparative analysis has been studied for a period of non tropical cyclonic activity (July 15-August 15, 1998) and a period of cyclonic activity during the formation and development of hurricane Bret (August 15-28, 1999). Hurricane Bret reached category four status before making landfall near the west coast of Gulf of Mexico during 18-23 August. NOAA buoy data from the National Data Buoy Center and GOES 8 satellite images were used in this study. The sea surface temperature, air temperature and wind speed were derived from the buoy data. Heat, momentum and latent heat fluxes were computed for periods of non cyclonic activity and cyclonic activity. The study suggested (a) that the aversge sea surface temperature over the Gulf of Mexico was 30° C, (b) a predominant 3-5 day oscillation in heat and latent heat fluxes ( ~ 120 W/m²) during the formation and development of hurricane Bret, and a week 3-7 day oscillation in heat flux (~11 W/m²) during the non cyclonic activity were observed, (c) that the wind speed (120 knots) was maximum at the peak of the heat flux maximum during the hurricane development.