Water mass properties derived from satellite observations in the Barents Sea

The Barents Sea is a region of deep water formation where Atlantic Water is converted into cooler, fresher Barents Sea Water. Barents Sea Water properties exhibit variability at seasonal, interannual and decadal timescales. This variability is transferred to Arctic Intermediate Water, which eventually contributes to the deeper branch of the Atlantic Meridional Overturning Circulation. Variations in Barents Sea Water properties are reflected in steric height (contribution of density to sea level variations) that depends on heat and freshwater content, and is a quantity usually derived from in situ observations of water temperature, salinity and pressure that remain sparse during winter in the Barents Sea. This analysis explores the utility of satellite observations for representing Barents Sea Water properties and identifying trends and sources of variability through novel methods. We present our methods for combining satellite observations of eustatic height (the contribution of mass to sea level variations), sea surface height and temperature, validated by in situ temperature and salinity profiles, to estimate steric height. We show that sea surface temperature is a good proxy for heat content in the upper part of the water column in the south‐eastern Barents Sea, and that freshwater content can be reconstructed from satellite data. Our analysis indicates that most of the seasonality in Barents Sea Water properties arises from the balance between ocean heat transport and atmospheric heat flux, while its interannual variability is driven by heat and freshwater advection. Plain Language Summary The Barents Sea is an Arctic continental shelf sea where inflowing warm salty water from the Atlantic Ocean loses heat to the atmosphere, gains freshwater from sea ice melt and rivers, and transforms into a water mass called Barents Sea Water. Variability and vertical structure of ocean temperature and salinity can be measured from ships, buoys and gliders that profile the ocean from surface to bottom, but are costly and to some degree limited by sea ice and weather. Satellites observe the ocean more frequently, and cover larger parts of it, but cannot measure below the surface. We combine different satellite measurements with novel physical and statistical techniques to infer ocean heat and freshwater content, integrated over the upper part of the water column. Using our satellite‐based reconstruction of upper ocean heat, we determine the seasonal ocean heat import is balanced by the warming of the atmosphere by the ocean. These results increase the utility of the available satellite measurements and demonstrates their potential for providing insight that can improve predictions about sea ice and ocean properties in this changing Arctic region.