Swell in the Pacific Ocean observed by SEASAT radar altimeter

Abstract

The first synoptic observations of ocean swell generation, propagation, and dissipation have been obtained from SEASAT radar altimeter measurements. The sequential significant wave height and surface wind speed measurements have been deduced from altimeter observations; by assuming that the Pierson and Moskowitz fully developed wave model applies, a model for determining minimum swell is used to generate three‐day average swell maps of the Pacific Ocean for the period June to October 1978, the SEASAT lifetime. The generation of numerous swell events was observed with the altimeter in the high‐latitude regions of the South Pacific Ocean (south of 40°S latitude), which was acting as a continuous swell source.

Regional differences in the northward propagation and dissipation patterns of different swell events have been analyzed. In their northward propagation the swell families generated in the Ross Sea neighborhood can impinge the coasts of North America with significantly more energy than the swells generated south of Australia. In the latter case, most of the swell energy is dissipated along the continental masses of Australia, New Zealand, and the South Pacific Islands. These results are a confirmation with satellite data of the earlier work on swell propagation in the Pacific Ocean performed with data from subsurface pressure transducers.