Atmospheric Variability Drives Anomalies in the Bering Sea Air-Sea Heat Exchange

High latitudes, including the Bering Sea, are experiencing unprecedented rates of change. Long-term Bering Sea warming trends have been identified, and marine heatwaves (MHWs), event-scale elevated sea surface temperature (SST) extremes, have also increased in frequency and longevity in recent years. Recent work has shown that variability in air-sea coupling plays a dominant role in driving Bering Sea upper-ocean thermal variability and that surface forcing has driven an increase in the occurrence of positive ocean temperature anomalies since 2010. In this work, we characterize the drivers of the anomalous surface air-sea heat fl uxes in the Bering Sea over the period 2010-22 using ERA5 fi elds. We show that the surface turbulent heat fl ux dominates the net surface heat fl ux variability from September to April and is primarily a result of near-surface air temperature and specific humidity anomalies. The airmass anomalies that account for the majority of the turbulent heat fl ux variability are a function of wind direction, with southerly (northerly) wind advecting anomalously warm (cool), moist (dry) air over the Bering Sea, resulting in positive (negative) surface turbulent fl ux anomalies. During the remaining months of the year, anomalies in the surface radiative fl uxes account for the majority of the net surface heat fl ux variability and are a result of anomalous cloud coverage, anomalous lower-tropospheric virtual temperature, and sea ice coverage variability. Our results indicate that atmospheric variability drives much of the Bering Sea upper- ocean temperature variability through the mediation of the surface heat fl uxes during the analysis period.