Meridional Eddy Heat Flux in the Kuroshio Extension Current

Abstract

A set of 19 zonal vertical sections of temperature were collected in 1975 with XBT observations at 80 km spacing, made from ships-of-opportunity transiting the mid-latitude North Pacific. In the region of the Kuroshio Extension Current, around 35°N, 165°E to 170°W, cross-spectral analysis reveals a significant 30° phase shift, upwards to the west, for the dominant mesoscale features of ?500 km wavelength. This phase shift implies that a poleward eddy flux of heat exists, associated with these mesoscale eddies. A simple calculation of the meridional eddy heat flux based on these results indicates an eddy flux of 3 ? 1014 W over the length of the Kuroshio Extension. This value is 17% of that estimated by Oort and Vonder Haar (1976) to be the total ocean heat flux at 40°N over the entire Northern Hemisphere.