85th AMS Annual Meeting

Tuesday, 11 January 2005: 2:45 PM
Annual cycle of equivalent ocean heat content and ocean heat transport divergence inferred from atmospheric heat budgets.
Kevin E. Trenberth, NCAR, Boulder, CO; and J. Fasullo
Net surface fluxes into or out of the ocean have been computed as residuals of the total heat budget of the Earth using top-of-atmosphere radiation and complete heat and energy budgets for the atmosphere. As the main ocean heat transports relate to the annual mean fluxes, the focus is on departures from the annual mean and the implied annual cycle in “equivalent ocean heat content”. We use the term “equivalent” because it includes any annual cycle in ocean heat transports, but those effects are relatively small in most places. By differencing our estimates from heat content estimates based on ocean observations, as analyzed by Levitus et al., we compute the annual cycle of implied convergence of heat by ocean transports. This process reveals some problems in the Levitus data over the southern hemisphere. In the northern hemisphere, good agreement exists with direct estimates of ocean heat content changes, showing how large and important the seasonal uptake and release of heat to the atmosphere is, while the ocean transports are modest. The most notable differences are in the tropics and especially from about 5 to 15°N, in association with the annual cycle in wind stress curl and North Equatorial Current.

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