Sentinel-1 SAR Observation of Internal Solitary Waves Generated at the South Orkney Plateau

A lot of Sentinel-1A/B synthetic aperture radar (SAR) observation taken from South Orkney Islands indicate that its southern plateau can be an oceanic hot spot for internal solitary waves (ISWs). The spatial distribution and physical parameters of these waves are disclosed for the first time. The statistical results show that observed ISWs have two main propagation paths towards south and east off the generation site and that they have an average wavelength of 300 m and crestlength around 80 km. Besides, most observed ISWs are generated before and after local spring tide. The barotropic body force is calculated to identify potential internal tides (ITs) generation locations. It is found that the 1 000 isobaths near 45°W can be an ideal internal tide generation site. We also calculate the generation time for eastward propagating ISWs at ideal internal tide generation site which validates the internal tide release mechanism. It shows the waves are form just to the west of the sill at the time of maximum westward flow and disintegrate into strong ISWs when westward tidal current slackens. Finally, we use the Benjamin-Ono equation in a two-layer mechanism to simulate the characteristic parameters of the studied ISWs. The derived wave amplitude and phase speed are around 9 m and 0.5 m/s respectively, but we lack in situ observation to verify.