A Study of Oceanic Fronts

Abstract

Oceanic fronts and frontal layers are defined. Temperature data obtained at two fronts in the equatorial Pacific are presented and a particular circulation, considered basic to the existence of a front, is proposed. Vertically isothermal warm water overlies the stable frontal layer. This suggests that vertical mixing in the isothermal water maintains the frontal layer in the same way that wind-induced vertical mixing maintains sharp thermoclines. The data suggest that the depth of vertical mixing is different in the warm and cool water masses adjacent to one of the fronts. It is suggested that the change in vertical mixing regimes contributes to the horizontal gradients of properties across this front.