Longevity of internal solitary waves in the Pacific Cold Tongue: synergies with SWOT

Analysis of satellite images from the SWOT mission provide unprecedent details of trains of Internal Solitary-like Waves (ISWs) in the central and eastern equatorial Pacific Ocean. A total of 226 ISWs were found between March 27 and September 10 (2024), 44 of which are directly associated with small-scale sharp fronts. Satellite synergies between the Ka-band Radar Interferometer (KaRIn) and optical imagery reveal that these waves propagate for long distances within the Pacific Cold Tongue (PCT). A selection of 21 cases shows that waves propagate on average for at least 19 h and may endure up to more than 48 h. These ISW trains may travel from one edge of the PCT, across its meridional width, to the other edge. Since ISWs transport mass and momentum and therefore convey information between the north and south equatorial fronts, we briefly discuss possible physical implications. • SWOT provides unprecedent details of ISWs in the Pacific Cold Tongue. • Synergies reveal ISWs last on average for 19.2 h with a maximum of 48 h. • ISWs may propagate the full meridional length of the Pacific Cold Tongue.