The aqueous turbulent layer at the air-sea interface plays an important role in determining interfacial fluxes. Here a method of determining the heat flux at such an interface is explored by simulating the effects of surface heating on the evolution of buoyancy driven turbulence. We find that the turbulence can be almost entirely eliminated when the source is of sufficient strength, depth, and duration. As the fluid cools, it is found to undergo an abrupt transition to turbulence which corresponds to a signature in the surface temperature. A simple one-dimensional conduction model is found to accurately describe the temporal response of the surface temperature during heating and cooling. (C) 2014 Elsevier Ltd. All rights reserved.