Latent heat flux over the North Atlantic Ocean - a case study

Abstract

Nimbus-7 SMMR data and ship observations are combined to compute the latent heat flux using the bulk aerodynamic method. Sea surface temperature (SST) and the surface humidity are determined with the microwave data. The surface wind field is derived from an analysis of ship observations of wind speed and surface pressure by means of a boundary-layer model by Bumke and Hasse. The microwave-derived SSTs are calibrated against those calculated from Advanced Very High-Resolution Radiometer (AVHRR) data. To get reliable results in the northern parts of the North Atlantic, only ascending (daytime) orbits of Nimbus-7 were used. Daytime data show a larger bias due to solar heating of the instrument but lack the complicating effects of differential cooling when the satellite enters the earth's shadow at the beginning of the descending orbits. -from Authors