ASSIMILATION OF ENVISAT ASAR WAVE MODE LEVEL 2 PRODUCT

摘要

The wave mode (WM) of Synthetic Aperture Radarrn(SAR) instruments provides detailed description of thernsurface sea state with global coverage. However, thernazimuthal cut-off (i.e. inability of SAR to resolves smallrnscale waves in the flight direction), restricts its usabilityrnfor some applications. ECMWF had been assimilatingrnSAR WM Level 1b (L1b) product operationally fromrnERS-2 and ENVISAT since January 2003. Thernoperational assimilation of ENVISAT ASAR WMrnLevel 2 (L2) product has never been realised due to itsrnminor negative impact. The results of variousrnassimilation experiments are presented and the resultsrnare discussed. The proper selection of quality controlrn(QC) criteria is critical in the success of WM L2 productrnassimilation. The impact of assimilating WM L2 rangesrnfrom being slightly positive to being slightly negative.