Impacts of Arctic freshwater export on the subpolar North Atlantic Ocean circulation

This study seeks to understand how the melting of Arctic ice and extra Arctic precipitation can influence the ocean currents in the North Atlantic. The study also asks how much of the Arctic meltwater and precipitation can be attributed to humans (anthropogenic influence)? The project will use verified and tested ocean models to determine the fate of Arctic water and the sources of unusually fresh water in the subpolar North Atlantic. Arctic waters will be tracked with several novel approaches, including artificial intelligence. For broader impacts, the project will provide understanding on the changes in the Arctic attributable to humans and their impact on the North Atlantic currents. These changes should influence global climate through the weakening of the climate-related Atlantic Meridional Overturning Circulation. Moreover, the project will support one graduate student and undergraduate students in research experiences. Results will be disseminated through typical academic activities and outreach to the general public. This study seeks to observe, understand and anticipate the export, propagation, and impacts of Arctic-derived fresh water on the subpolar North Atlantic. The study will identify the timing and character of the Arctic anthropogenic freshening signal in the subpolar North Atlantic through specific activities related to a) the fates of Arctic freshwater anomalies, b) the sources of subpolar North Atlantic freshwater anomalies, and c) preparations for the impacts of Arctic freshwater export on the subpolar North Atlantic. Novel tools will be applied for Eulerian anomaly tracking and Lagrangian trajectory analysis to outputs from model state estimates (ECCO, ASTE), reanalysis (ORAS5), forced high-resolution ocean model (LLC4320), and coupled projections (CESM2 LENS). For broader impacts, the project will provide understanding on the Arctic anthropogenic freshening and its impact on the subpolar North Atlantic, which influences global climate through the buoyancy-forced weakening of the Atlantic Meridional Overturning Circulation. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.