Estimation of Surface Freshwater Fluxes in the Arctic Ocean Using Satellite-Derived Salinity

Abstract

The temporal and spatial distribution of sea surface salinity (SSS) is not well known in the Arctic region, and only recent satellite-derived measurements and models have allowed for potential enhancement, though their accuracy remains uncertain. We use NASA’s Soil Moisture Active Passive (SMAP) and the European Space Agency’s Soil Moisture Ocean Salinity (SMOS) to investigate the variability of SSS in the Arctic from 2015 to 2017, as well as to calculate surface advective freshwater fluxes. These data sets are compared with Argo and European Center for Medium-Range Weather Forecasts Ocean Reanalysis version 4 (ORAS) to assess the ability of satellites in detecting freshwater fluxes. Salinity and surface freshwater fluxes are estimated for the Bering Strait and Barents Sea Opening (BSO). In this study, we have compared the Jet Propulsion Laboratory’s (JPL) SMAP salinity to the remote sensing system’s (RSS) SMAP salinity product, as well as the The Centre Aval de Traitement des donneees SMOS salinity product. There is disagreement between the reanalysis product and satellites on the mean and variability of surface freshwater fluxes in the BSO; however, the meridional fluxes of the satellites and reanalysis product were significantly correlated within the Bering Strait. This shows the capability of using satellites to measure surface freshwater fluxes in this pathway. However, the discrepancies between satellite-derived SSS and fluxes in other regions of the Arctic Ocean emphasizes the need to increase in situ monitoring to help validate satellites in the higher latitudes.