Estimation of sea surface topography in the Norwegian sea using gravimetry and Geosat altimetry

Abstract

An analysis of the quasi-stationary sea surface topography (QSST) is carried out in the Norwegian Sea region (54°<o<72°, -25°<λ<20°) using marine gravimetry and one year of Geosat ERM altimetry. As reference models the geopotential model OSU91A and the QSST model OSU89D were used. Two procedures to extract the QSST from mean sea surface heights and gravity anomalies were tested. Spherical FFT techniques were applied in both procedures. The results show that QSST associated with wavelength shorter than 4000 km exists. Relative to the OSU89D model the QSST was found to have a variance of (0.219 m)2 and a correlation length of 1.105°. The circulation pattern recovered in this paper agree with results of oceanographic analysis.