Mesoscale Sea Surface Salinity in the Algerian Basin observed through SMOS and ABACUS glider data

The Algerian Basin is a key component of the general circulation in the Western Mediterranean Sea. The presence of both fresh Atlantic water and more saline Mediterranean water gives the basin an intense inflow/outflow regime and complex circulation patterns. Energetic mesoscale structures that evolve from meanders of the Algerian Current into isolated cyclonic and anticyclonic eddies dominate the area, with marked repercussions on biological activity. In recent years, several studies have demonstrated the advantages of combined use of autonomous underwater vehicles, such as gliders, with remotely sensed products. In this framework, an important contribution could come from a new generation of enhanced sea surface salinity (SSS) products, i.e. Soil Moisture and Ocean Salinity (SMOS), Soli Mosture Active Passive (SMAP) and Aquarius. Here we present a preliminary study to assess the advantages of using the enhanced SMOS SSS products obtained through a new methodology using a combination of debiased non-Bayesian retrieval, DINEOF (Data Interpolating Empirical Orthogonal Functions) and multifractal fusion with high resolution Sea Surface Temperature (OSTIA SST) maps for improving their spatial and temporal resolution in the Western Mediterranean Sea (Olmedo et al., 2018). The Algerian Basin SSS described by the new SMOS maps have been compared with the in situ high resolution glider measurements collected in the framework of the ABACUS series observational program conducted in the Algerian Basin during fall 2014 – 2017 and spring 2017 – 2018 (Cotroneo et al., 2016; Aulicino et al., 2018). The achieved results show that i) the enhanced SMOS products well represent the salinity patterns described by in situ SSS; ii) the mesoscale structures described by SMOS in the Algerian Basin coincide with those identified by gliders and described by altimetry and MODIS images.