Cold wake of Hurricane Frances

Abstract

An array of instruments air‐deployed ahead of Hurricane Frances measured the three‐dimensional, time dependent response of the ocean to this strong (60 ms −1 ) storm. Sea surface temperature cooled by up to 2.2°C with the greatest cooling occurring in a 50‐km‐wide band centered 60–85 km to the right of the track. The cooling was almost entirely due to vertical mixing, not air‐sea heat fluxes. Currents of up to 1.6 ms −1 and thermocline displacements of up to 50 m dispersed as near‐inertial internal waves. The heat in excess of 26°C, decreased behind the storm due primarily to horizontal advection of heat away from the storm track, with a small contribution from mixing across the 26°C isotherm. SST cooling under the storm core (0.4°C) produced a 16% decrease in air‐sea heat flux implying an approximately 5 ms −1 reduction in peak winds