Arctic Freshwater Content measured with SMOS and TOPAZ reanalysis

• Main Authors: Umbert, Marta, Andrés Marruedo, Eva de, Sánchez Urrea, María, Gabarró, Carolina
• Other Authors: European Space Agency
• Format: Still Image
• Language: unknown
• Published: 2023
• Subjects: Arctic; Arctic Ocean; Subarctic
• Online Access: http://hdl.handle.net/10261/362954

Arctic-Subarctic Ocean Fluxes (ASOF) Meeting, 10-12 May 2023, Gran Canaria, Spain According to several studies, the liquid freshwater content (FWC) in the Beaufort Gyre has considerably increased over the last two decades. Variations in freshwater fluxes within the Arctic likely affect the global thermohaline circulation and have an impact on the global climate. However, the exact effect of the Arctic freshwater increase remains unclear due to the scarcity of measurements in the region. Traditionally, the Arctic Ocean’s FWC has been estimated using in situ measurements, as well as with the combination of Gravity Recovery and Climate Experiment (GRACE) and altimetry satellite data. In this work, we have computed the FWC combining sea surface salinity from the Soil Moisture and Ocean Salinity (SMOS satellite mission) and in-depth ocean salinity from TOPAZ4b reanalysis. The SMOS SSS v3.1 product is available from 2012 to 2019, therefore we have computed the FWC during that period setting Sref = 34.8 psu as the salinity reference value. Furthermore, we aimed to determine whether sea surface salinity (SSS) variations could serve as a proxy for FWC variability in certain regions of the Arctic Ocean. We found that the FWC computed using salinity from SMOS and TOPAZ together can be very similar to that previously reported from in situ observations, depending on the surface layer thickness where we impose SMOS SSS. Therefore, we attempted to determine the optimal surface layer thickness, examining its impacts at 5, 10, 15, and 20 m depth. We observed that the SMOS surface layer is fresher than TOPAZ 4b, and that the variation of the first salinity layer depth has a non-negligible impact on the computed FWC. According with previous studies, we would like to study if SMOS SSS could be a proxy of FWC in some Arctic regions This research is being conducted within the framework of European Space Agency ESA ARCTIC+SSS project and the Spanish-funded ARCTIC-MON project