Surface Thermal Boundary Condition for Ocean Circulation Models

Abstract

By employing a heat budget analysis appropriate to zonally and time averaged conditions within the atmosphere, it is shown that the net downward heat flux Q at the ocean's surface can be expressed as Q = Q2 (TA*–Ts), where TA* is an apparent atmospheric equilibrium temperature, Ts the sea surface temperature, and Q2 a coefficient determined from the zonally and time averaged data. The latter coefficient, which is of the order of 70 ly day−1 (°C)−1, varies with latitude by as much as 20%. It is suggested that the use of the above relation as a flux-type thermal boundary condition would allow for large-scale thermal coupling of ocean and atmosphere. The more common use of specified Ts as a boundary condition clearly does not allow for such coupling.