Sea Surface Topography Estimation with Infrared Satellite Imagery

Abstract

Sea surface flow derived from displacements of surface patterns in sequential NOAA-6 AVHRR (11 micron band) satellite images yield coherent nonuniform distributions of velocity vectors, An analytic representation of flow over the region of the distribution is obtained by performing a least-squares regression analysis for coefficients of a streamfunction expansion that is expressed in terms of trigonometric bash functions. Sea surface topography is estimated with the streamfunction by employing a geostrophic approximation. An application is made to a portion of the Oyashio Frontal Zone in the northwestern Pacific that includes the First and Second Oyashio Intrusions and an anticyclonic eddy. A horizontal map of a local rotational perturbation property is calculated for this region as a further example of the use of the streamfunction analysis.