Lee-Lueng Fu (JPL, USA); Maarten Buijsman (USM, USA); Gautier Bardi de Fourtou (MIT, USA); Thomas Lu (JPL, USA); Jinbo Wang (Texas A & M, USA); Aurelien Ponte (IFREMER, France)

Internal solitary waves (ISWs) are some of the most striking oceanic signals seen in SWOT imagery. While ISWs have been observed for a long time, we have not had systematic global measurements of their amplitudes, until now. Because SWOT measures sea surface height — a variable that provides dynamical insight — we can explore beyond their kinematics toward quantifying the magnitude and space-time variability of their energy fluxes. ISWs are the result of the direct forcing of tidal currents over bottom topography, as well as the nonlinear steepening of the larger-scale internal tide. While we generally know the energy input into the internal tides, the energy input into the ISWs is less well constrained. Ultimately, this energy contributes to ocean mixing. In this presentation, we first focus on the Mascarene Plateau in the Indian Ocean, where ISWs radiate from an underwater sill with SSH amplitudes up to 30 cm and wavelengths of 10 to 20 km. We map the time and space variability of the ISWs using both CalVal and science orbits and characterize the decay of the ISWs from rough topography and radial spreading. Next, we zoom out to explore global ISW activity, based on a deep learning approach to detect ISWs in the SWOT data.