Laura Saraceno (CIMA/CONICET-UBA, Argentina); Florence Birol (LEGOS, France); Maristella Berta (CNR-ISMAR, Italy); Alberto Piola (University of Buenos Aires, Argentina); Claudia Simionato (CIMA/CONICET-UBA, Argentina); Silvia Romero (Servicio de Hidrografía Naval, Argentina); Giuliana Berden (University of Victoria , Canada); Nicolas Bodnariuk (IPSL-CNRS, France); Valeria Guinder (Instituto Argentino de Oceanografía , Argentina); Matias Dinápoli (CIMA/CONICET-UBA, Argentina); Carola Ferronato (Instituto Argentino de Oceanografía , Argentina); Sebastian Cornejo-Guzmán (CIMA/CONICET-UBA, Argentina); Melina Martinez (CIMA/CONICET-UBA, Argentina); Urricariet Milagro (CIMA/CONICET-UBA, Argentina); Fernando Becker (Servicio de Hidrografía Naval, Argentina); Ornella Silvestri (Servicio de Hidrografía Naval, Argentina); Martin Rivarossa (INIDEP, Argentina); Fernando Ramirez (Instituto Argentino de Oceanografía , Argentina); Candela López Fidel (Universidad de Buenos Aires, Argentina); Celeste Antieco (Servicio de Hidrografia Naval , Argentina)

The main objective of PATASWOT is to enhance our understanding of the physical processes affecting the Patagonian continental shelf and adjacent open ocean using SWOT data, traditional satellite altimetry, in situ observations and model outputs. This objective is guided by the following key research questions: (Q1) What are the main physical drivers underlying the high biological activity observed over the Patagonian shelf and slope? (Q2) Does the Malvinas Current (MC) act more as a blender or as a barrier between open ocean and shelf waters? (Q3) How are the lower levels of the trophic web, –nutrients and phytoplankton- structured within the water column and how are these distributions associated with the physical characteristic of water masses on the Patagonian shelf, slope, and beyond the MC into the open ocean? To address these questions, we propose the following specific objectives: i) Validate SWOT data and geophysical correction against in situ data in the Patagonian continental shelf and open ocean; ii) Identify the physical processes measured by SWOT during the initial 1-day repeat orbit; Iii) Characterize the water exchange between the Patagonian shelf and open ocean; iv) Discern submesoscale dynamics that modulate the distribution of surface chlorophyll, heat and carbon fluxes; v) Assess the short-term evolution of the phytoplankton community composition and biomass. The required data will be obtained through Eulerian and Lagrangian experiments. These experiments will be conducted during an oceanographic cruise on R/V Falkor (too) scheduled for September-October 2025 on the upper slope of the shelf-break. The Eulerian experiment will include physical observations (temperature, pressure, salinity, currents) using three fixed moorings. The Lagrangian experiment will involve deploying a dense array of drifters (N = 54) drogued at depths of 50 cm and 15 m. The research vessel will track the drifters, and multiple water column samples will be collected at various depths. Additionally, time series of in situ current velocities and sea level measurements are already available to validate SWOT observations during the Cal/Val period over the Patagonian shelf, as well as 23 Lagrangian trajectories collected in the Brazil Current.