Sea Surface Salinity Variability in the Gulf of Anadyr: Inferences From Satellite Observations and a Coupled Ice‐Ocean Model

Abstract Analysis of satellite‐derived sea surface salinity (SSS) from SMAP and SMOS between 2015 and 2023 reveals distinct patterns of spatial and temporal variability in the Gulf of Anadyr (GA) in the northwestern Bering Sea. In particular, both products consistently capture anomalously fresher SSS patterns in summer 2021. Similar patterns are reproduced in a 2‐km resolution coupled ice‐ocean model simulation of the Bering Sea using the Regional Ocean Modeling System. The model is analyzed to understand the mechanisms driving SSS variability in the GA. In 2021, ice persists in the GA into June, leading to the anomalously fresher surface conditions when the ice eventually melts. The gulf‐averaged sea ice volume equation term balance analysis is performed to understand the mechanisms driving changes in the sea ice volume that in turn drive SSS anomalies. On the seasonal time scale, during the freezing season, sea ice volume in the GA increases primarily due to local thermodynamic production. Transport in and out of the GA is a substantial contributor to shorter term variability. Large ice production and less ice export result in persistent ice in 2021. Melting this ice in the GA creates the SSS anomaly pattern detected from space. Model results show that area‐averaged SSS and volume‐averaged salinity anomalies vary similarly during the freezing season but decouple during the melt season. Ice freeze/melt, boundary transport, and Anadyr River discharge are of comparable importance for the volume‐averaged salinity budget in the GA.