Hemispheric asymmetry of oceanic heat budget in the Equatorial Atlantic and Eastern Pacific

Abstract

The oceanic heat budget is studied on the basis of ship observations during 1911–70 compiled by one degree square areas. The clockwise turning cross-equatorial surface air flow is conducive to upwelling to the South and downwelling to the North of the Eastern Pacific and Atlantic Equator, particularly during Northern summer. The wind-induced vertical motion field is considered a factor in maintaining the cold water tongues immediately to the South, and the strong temperature increase northward across the Equator. Net radiation is only slightly higher in the Southern hemisphere equatorial zone, but sensible and latent heat flux are greatly reduced in the cold water regions, especially in Northern summer. As a result, the ocean exports heat at the rate of 53 and 62 W m -2 to the South of the Atlantic and Pacific Equator, respectively, compared to an export of only 29 and an import of 3 W m -2 in the Northern hemisphere equatorial zone. DOI: 10.1111/j.2153-3490.1977.tb00764.x