An Evaluation of the Net Tropical Ocean Surface Heat Flux from Atmospheric and Ocean Reanalysis

Abstract:

We investigate the net surface heat flux climatology and trends over the tropical oceans (30^oS - 30^oN) as represented in atmospheric and oceanic reanalysis products. In atmospheric reanalysis products the net ocean surface heat flux is calculated as a residual of the surface energy budget. For ocean reanalysis products we derive the net surface heat flux as the sum of the mean mixed layer heating rate and the net horizontal and vertical heat fluxes. We evaluate reproducibility of the net tropical ocean surface heat flux climatology and trend in various reanalysis products to assess how well the surface air-sea heat exchange is represented in ocean and atmospheric reanalyses, by measure of their spatial and temporal corroboration. The direct comparison of the net ocean surface heat flux between atmospheric and ocean reanalyses tests the surface energy budget of atmospheric reanalyses with the mixed layer energy budget of ocean reanalyses. Preliminary results suggest that there is strong agreement among the various atmospheric reanalyses in the net tropical ocean surface heat flux mean value and three year running mean trend anomalies from 1980 - 2010. We expect less agreement among ocean reanalyses, potentially due to the great disparity of vertical and horizontal resolutions, diversity of assimilated data sets, and subsequent method of variable calculation with depth.