Upper Ocean Response to Tropical Cyclone Wind Asymmetries

The most apparent effect of a tropical cyclone on the upper ocean is the marked cooling of sea surface temperature (SST) that is clearly seen in Advanced Very High Resolution Radiometer (AVHRR) images of SST. As a storm intensifies, the increasing wind speed may increase evaporation and supply the storm with the necessary source of heat for further intensification. However, the significant SST reduction induced by the increasing wind speed leads to reduced air-sea fluxes thus decreasing the storm intensity. In the context of extra tropical transition, the scales of upper ocean thermal and momentum response due to the passage of tropical cyclones is reviewed and the ocean response is simulated using a numerical ocean model for symmetric and asymmetric components of the wind field of hurricane Gilbert (1988) in the Gulf of Mexico.