Instantaneous near surface air temperature and sensible heat flux fields during the SEMAPHORE experiment using satellite data

A new technique was developed to retrieve near surface instantaneous air temperatures and turbulent sensible heat fluxes using satellite data during the SEMAPHORE experiment, which was conducted in 1993 under mainly anticyclonic conditions. The method is based on a regional, horizontal atmospheric temperature advection model whose inputs are wind vectors, sea surface temperature fields, air temperatures around the region under study, and three constants derived from aircraft measurements. The intrinsic rms error of the method is 0.8 K in terms of air temperature and 10 W.m-2 for the fluxes, both at 0.16 degree and 1.125 degree resolution. The retrieved air temperature and flux horizontal structures are in good agreement with fields from two operational General Circulation Models. The application to SEMAPHORE data involves ERS-1 wind fields, high resolution reanalyzed SST maps, ECMWF air temperature boundary conditions, and aircraft data. The rms errors obtained by comparing the estimations to Research Vessel measurements are 0.8 K and 10 W.m-2.