OSNAP West

A US-led international effort, Overturning in the Subpolar North Atlantic Program (OSNAP), has provided a continuous record of the full-water column, trans-basin fluxes of heat, mass, and freshwater in the subpolar North Atlantic since 2014, in partnership with the UK, Netherlands, Canada and Germany. Results from the first four years of OSNAP observations have challenged the current understanding of overturning circulation in the subpolar North Atlantic. This grant provides funding for an additional four years of observations in order to deliver to the community a ten-year time series of the meridional overturning, heat and freshwater fluxes in the subpolar basin. Variations in these quantities have been invoked to explain changes in a wide range of physical, chemical and biological parameters in the North Atlantic, Nordic Seas, and Arctic Ocean. Thus, by quantifying Atlantic meridional overturning variability and understanding its drivers, OSNAP is providing a critical first step towards addressing societally-relevant, interdisciplinary questions concerning the melting of Greenland ice and Arctic sea-ice, heat content in the Arctic Ocean, climate of the Nordic Seas, and anthropogenic carbon storage. The researchers will actively engage the broader international communities through four workshops, each targeting a societally relevant theme: 1) ocean biogeochemistry and carbon sequestration; 2) overturning in ocean models; 3) Arctic cryosphere; and 4) Nordic Seas variability. Two new postdocs and one graduate student will be supported in this phase of OSNAP and will benefit from the diversity of methodologies and exposure to the large number of OSNAP international scientists. In addition, approximately 20 graduate students from different US and international institutions will receive field training through participation in OSNAP cruises through 2024.