Some Evidence of Cool Surface Water Pools Associated with Mesoscale Downdrafts during GATE

Abstract

A pool of cool surface water was observed on 15 July 1974 during the GATE experiment, where down-drafts were present inside the cloud cluster. Downdrafts are assumed to destroy the buoyant moist plume convection that normally exists in the tropical mixed layer. The vertical fluxes of heat and moisture from the ocean are thus increased by the lowered equivalent potential temperatures and the increased winds which am produced by the downdrafts. These enhanced fluxes may induce a sea surface temperature cooling if they last for a few hours. The cooling due to the downdrafts is of a magnitude at least comparable to that produced by precipitation.