In this paper we study the impact of ocean coupling on landfalling tropical cyclones using the GFDL/URI coupled hurricane-ocean model with idealized atmospheric and oceanic conditions. The focus is on the coastal sea surface temperature response and its effect on hurricanes during landfall. In particular, we investigate the effect of hurricane-induced sea surface heat fluxes on SST changes and its feedback on hurricane intensity change.

It is well known that surface heat fluxes play an insignificant role in the sea-surface cooling in the deep ocean which is mostly caused by the vertical mixing in the upper ocean. However, we find it is not the case in shallow water regions. It turns out the surface heat fluxes play the dominant role in near coastal areas during hurricane landfall and may cause a significant decrease of the SST. For example, for a slow moving, category 2 hurricane making landfall over 25 m and 15 m waters (characteristic values in the northern Gulf of Mexico shelf) the minimum surface pressure reduction can reach up to 8 hPa and 13 hPa correspondingly.