Improved BEC SMOS Arctic Sea Surface Salinity product v3.1

Abstract. Measuring salinity from space is challenging since the sensitivity of brightness temperature (TB) to sea surface (SSS) low (about 0.5 K psu?1), while SSS range in open ocean narrow 5 psu, if river discharge areas are not considered). This translates into a high accuracy requirement radiometer 2–3 K). Moreover, TB at cold waters even lower (0.3 making retrieval more challenging. Due this limitation, ESA launched specific initiative 2019, Arctic+Salinity project (AO/1-9158/18/I-BG), produce an enhanced Arctic product with better quality and resolution than available products. paper presents methodologies used new SMOS (Martínez et al., 2019) . The consists 9 d averaged maps EASE 2.0 grid 25 km. freely distributed Barcelona Expert Center (BEC, http://bec.icm.csic.es/, last access: January 2022) DOI number https://doi.org/10.20350/digitalCSIC/12620 2019). major change its improvement effective spatial that permits monitoring mesoscale structures (larger 50 km), which benefits monitoring.