Wind driven ocean circulation features in the Gulf of Tehuantepec, Mexico, revealed by combined SAR and SST satellite sensor data
The Gulf of Tehuantepec is a heavily-fished area where the levels of primary productivity have been compared with the rich water of the central Gulf of California and the upwelling area off Baja California. Such high productivity is the result of strong winter upwelling events as a result of locally intense jets of wind off the land. These jets are responsible for upwelling, vertical entrainment of cool water along the wind axis, and the spin-up of mesoscale anticyclonic eddies of warmer water that contrast with the cool waters normally present. The thermal contrast between some of these features and the waters surrounding them has enabled the mesoscale coastal circulation of the Gulf of Tehuantepec to be studied with the aid of satellite-borne infra-red sensors. In this paper we examine whether SAR images can play a useful role in observing the mesoscale structures characteristic of the Gulf of Tehuantepec, and whether a combination of nearly coincident SAR and infra-red images can provide new information about the physical processes over a range of length scales. We conclude that the SAR could be used to monitor this air-sea interaction process even when cloud cover prevents the use of infra-red sensors.