ECMWF and ERS-1 surface winds over the Arabian Sea during July 1995

Abstract

The European Centre for Medium-Range Weather Forecasts (ECMWF) and Institut Francais Pour la Recherche et l'Exploitation de la Mer European Remote-Sensing Satellite, named IFR2, surface wind velocity data products are compared during July 1995 over the Arabian Sea. Substantial differences were found. The central positions of the maximum isotach were separated by 450 km, and the ECMWF maximum isotach was 2 m s-1 higher than that of IFR2. IFR2 wind components contained about 10 times more variance than ECMWF winds for horizontal distances from 50 to 250 km. Along the 8.5°N southern boundary of the Arabian Sea, ECMWF southward Ekman transport was higher than that of IFR2 by an amount that could be observed with current measurements. The ECMWF and IFR2 difference in upward transport of water into the Ekman layer, computed from wind stress curl, was large enough to measure.