Internal Waves Generated in the Straits of Gibraltar and Messina: Observations from Space

Abstract

The Straits of Gibraltar and Messina are areas where strong internal solitary waves are generated by the interaction of tidal currents with shallow underwater ridges located within the straits. Remote sensing techniques and numerical simulations have been very instrumental in studying the generation and propagation of internal solitary waves in these sea areas. It was a synthetic aperture radar (SAR) image acquired by the American Seasat satellite in 1978 that first revealed that long internal waves are generated in the Strait of Messina. Furthermore, SAR images acquired by the European Remote Sensing satellite ERS-1 and ERS-2 have revealed that trains of internal solitary waves generated in the Strait of Gibraltar propagate mostly eastward into the Mediterranean Sea, while westward propagating wave trains can only be supported by a seasonal thermocline.