Variability of Spacebased Sea Surface Salinity and Freshwater Contents in the Hudson Bay

We investigate the variation of sea surface salinity (SSS) retrieved in the Hudson Bay from L-band microwave measurements of SMAP and SMOS for open water seasons 2015-2017. We analyzed the differences between three SSS products (SMAP from JPL and RSS, and SMOS from BEC), and assessed in the context of seasonal and inter-annual variation of the freshwater contents, considering river runoffs, sea ice changes, and surface forcing (P-E). We found SMAP JPL (V4.2) shows reasonable responses to the freshwater inputs which is dominated by the sea ice change particularly early in the melting season. This result demonstrates the potential of currently available L-band missions in monitoring cryospheric changes; also underscore urgent needs of in situ salinity measurements in the region to improve retrieval algorithms.