Estimates of Mass, Momentum and Kinetic Energy Fluxes of the Gulf Stream

Abstract

Mass, momentum and kinetic-energy fluxes in the Gulf Stream have been estimated from hydrographic data taken by Fuglister in the Gulf Stream ?60 project; the data cover the Stream as it flows eastward, from south of Georges Bank to the Grand Banks. The results are compared to a two-layer, constant potential-vorticity inertial-jet model and reasonable agreement is found. Error estimates based on the model and the data indicate errors of up to about 30% for mass and momentum and 50% for kinetic energy fluxes. All three fluxes exhibit considerable downstream divergence; the dynamical implications of these divergences for the region are assessed, and importance of nonlinear effects in the Stream is discussed. It is suggested that there may be a significant conversion of kinetic to potential energy and that this mechanism ought not be excluded a prior by examining primarily linear models of the Stream.