BASIN-SCALE, HIGH-WAVE-NUMBER SEA-SURFACE WIND FIELDS FROM A MULTIRESOLUTION ANALYSIS OF SCATTEROMETER DATA

A numerical technique sensitive to both spectral and spatial aspects o f sea surface wind measurements is introduced to transform the irregul arly sampled satellite-based scatterometer data into regularly gridded wind fields. To capture the prevailing wavenumber characteristics (po wer-law dependence) of sea surface wind vector components, wavelet coe fficients are computed from the scatterometer measurements along the s atellite tracks. The statistics of the wavelet coefficients are then u sed to simulate high-resolution wind components over the off-track reg ions where scatterometer data are not available. Using this technique, daily wind fields with controlled spectral features have been produce d by combining the low-wavenumber wind fields from ECMWF analyses with the high-wavenumber measurements from the ERS-1 scatterometer. The re sulting surface wind fields thus reflect nearly all available measurem ents affecting surface wind, including the synoptic surface pressure. The new surface wind forces a basin-scale quasigeostrophic ocean model such that the average circulation and energetics are consistent with the previous studies, in which purely synthetic high-wavenumber wind f orcing was used.