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Sea surface salinity (SSS) anomalies and near-surface thermohaline stratification are key parameters to improve our understanding of sea ice retreat and formation in polar regions. Since 2010, the remote sensing salinity missions ESA Soil Moisture Ocean Salinity (SMOS) and NASA Soil Moisture Active Passive (SMAP) offer unprecedented SSS observations globally (SSSSMOS and SSSSMAP, respectively). In this study, we compare these observations with in situ salinity observations (SSSin‐situ) made during the NASA salinity field campaign Salinity and Stratification at Sea Ice Edge (SASSIE) during the fall of 2022. The SASSIE SSSin‐situ were collected by nine different platforms: Castaway and Underway conductivity–temperature–depth (CTD), Wave Gliders, Thermosalinograph, Snake salinity, Surface Wave Instrument Float with Tracking (SWIFT) drifters, Upper Temperature of the Polar Oceans (UpTempO) buoys, Jet Surface Salinity Profiler (Jet-SSP), and Autonomous Lagrangian Thermometric Observer (ALTO) and Air-Launched Autonomous Micro Observer (ALAMO) profilers. Because satellite SSS retrievals are impacted by land and sea ice contaminations, cold temperatures, and surface roughness, mean differences, root-mean-square difference (RMSD), and standard deviation (STD) between satellite SSS and SSSin‐situ are examined as a function of distance from the coast and sea ice edge, sea surface temperature (SST), and wind speed. We find that SSSSMOS and SSSSMAP are well correlated (0.66 and 0.78, respectively) with similar RMSD when compared with SSSin‐situ. Close to the coast (0–150 km), SSSSMAP compares better with SSSin‐situ with RMSD (<2 g kg−1) lower than that from SSSSMOS. Near the sea ice edge (0–150 km), SSSSMOS compares better with SSSin‐situ with RMSD (<2.5 g kg−1) lower than that from SSSSMAP. In cold water (SST < 1.5°C) and low wind speed conditions (<7 m s−1), both SSSSMOS and SSSSMAP are consistent with each other. The RMSD between SSSSMAP and SSSin‐situ decreases considerably (<1 g kg−1) when SST > 1.5°C, while the RMSD between SSSSMOS and SSSin‐situ shows less dependence on SST. 

Abstract Climate model projections suggest a substantial decrease of sea ice export into the outflow areas of the Arctic Ocean over the 21st century. Fram Strait, located in the Greenland Sea sector, is the principal gateway for ice export from the Arctic Ocean. The consequences of lower sea ice flux through Fram Strait on ocean dynamics and primary production in the Greenland Sea remain unknown. By using the most recent 16 years (2003–2018) of satellite imagery available and hydrographic in situ observations, the role of exported Arctic sea ice on water column stratification and phytoplankton production in the Greenland Sea is evaluated. Years with high Arctic sea ice flux through Fram Strait resulted in high sea ice concentration in the Greenland Sea, stronger water column stratification, and an earlier spring phytoplankton bloom associated with high primary production levels. Similarly, years with low Fram Strait ice flux were associated with a weak water column stratification and a delayed phytoplankton spring bloom. This work emphasizes that sea ice and phytoplankton production in subarctic “outflow seas” can be strongly influenced by changes occurring in the Arctic Ocean.