Fine-Scale ocean currents from integrated multi-platform experiments and numerical simulations: contribution to the new SWOT satellite mission. Cruise Plan (FaSt-SWOT, PID2021-122417NB-I00)

Surface Water & Ocean Topography (SWOT) is the first satellite altimetry mission to measure the elevation of nearly all water on Earth’s surface. SWOT will provide high-resolution maps of the water surface topography over the open and coastal oceans, lakes rivers and reservoirs. After two decades of preparation , SWOT was launched on December 2022. For approximately the first 180 days of the mission, SWOT is in a 1-day repeat orbit for cal/val. This document represents the cruise plan of the FaSt-SWOT field campaigns co-led by IMEDEA(CSIC-UIB) and SOCIB as a contribution to the SWOT Science Team and SWOT-AdAC consortium. FaSt-SWOT multi-platform experiments took place in the Balearic Sea in April-May 2023 during the SWOT satellite mission fast-sampling phase. The generals objectives of these experiments were (1) to validate the first observations provided by the new altimeter mission during the calibration/validation phase and (2) to improve the characterization of oceanic fine scales through the combined use of in-situ multi-platform and satellite data in synergy with numerical models and innovative computational techniques. The campaigns have assessed the actual capability to map SSH variability over a range of scales (30-100 km) traditionally not resolved by conventional altimeters. A unique aspect of the FaSt-SWOT experiments is the combination of concurrent multi-scale ship-based instruments, autonomous platforms, and satellite observations with ad hoc modeling simulations, enabling the evaluation of underlying mechanisms. FaSt-SWOT federates two multiplatform in situ experiments, combining glider, drifter, ship observations together with satellite observations and high-resolution data-assimilative numerical simulations. Advanced Observing System Simulation Experiments (OSSEs) and new tools of artificial intelligence have been performed to optimize the sampling strategies. This document includes the plans for the cruises and it will be complemented with the cru