Variability of the tropical and subtropical ocean surface latent heat flux during 1989-2000

Abstract

We assess the consistencies and discrepancies of the interannual variability and decadal trend of the ocean surface latent heat flux (LHF) for the period 1989-2000 among two satellite-based data sets and two reanalysis products over the tropics and subtropics. The data sets show encouraging agreement on the spatial/temporal variations of the LHF, particularly during 1992-1997, but some discrepancies are noticed. These discrepancies are primarily caused by the differences of the input meteorological state variables used to calculate LHF, particularly for the air specific humidity. Both the satellite-based data sets and reanalysis products show a statistically significant decadal-scale positive trend in the LHF, which is independent of the El Niño-Southern Oscillation, with the strongest trends in the subtropical Southeast Pacific and Southeast Indian Ocean. This trend in the LHF is associated primarily with an increasing trend of the surface wind speed. Copyright 2006 by the American Geophysical Union.