Fitting dynamic models to the Geosat sea level observations in the tropical Pacific Ocean. Part II: a linear, wind-driven model

Abstract

The Geosat altimeter sea level observations in the tropical Pacific Ocean are used to evaluate the performance of a linear wind-driven equatorial wave model. The question posed is the extent to which such a model can describe the observed sea level variations. The Kalman filter and optimal smoother are used to obtain a solution that is an optimal fit to the observation in a weighted least-squares sense. The total mean variance of the Geosat sea level observations is 98.1 cm2, of which 36.6 cm2 is due to measurement errors, leaving 61.5 cm2 for the oceanographic signal to be explained. The model is found to account for about 68% of this signal variance, and the remainder is ascribed to the effects of physical mechanisms missing from the model. -from Authors