A method for identifying and analysing submesoscale eddies in SWOT data

Submesoscale eddies have traditionally eluded identification by conventional altimetry due to their unique temporal and spatial scales. However, the successful launch of the Surface Water and Ocean Topography (SWOT) satellite in December 2022 provides unprecedented high-resolution observational data, opening a new avenue for understanding submesoscale eddies. In this study, an existing mesoscale eddy detection method was modified and applied to SWOT data for the identification of submesoscale eddies. The feasibility and accuracy of this approach were validated using vertical temperature profile (VTP) data. The results indicated that submesoscale eddies with strong amplitudes, large spatial scales and significant separation from mesoscale eddies exhibit distinct VTP characteristics. In contrast, identifying weaker submesoscale eddies remains challenging due to data resolution limitations. Future research should prioritize the acquisition of higher-resolution oceanographic measurements to enhance the refinement of identification methods. Furthermore, addressing the current limitations of SWOT, particularly regarding temporal resolution and along-track observation width, is critical for advancing the application of next-generation altimeter technology in eddy studies.