The boundary current system of the eastern Labrador Sea based on a decade of mooring measurements

This project seeks to analyze 10-years of data from the West Greenland mooring array in the eastern Labrador Sea that is part of the multi-national Overturning in the Subpolar North Atlantic Program (OSNAP) which started in 2014. The first decade of the ONSAP data collection effort is thus just complete, providing an unprecedented opportunity to determine changes in the North Atlantic Ocean, including changes resulting from ice sheet melting on Greenland and in the Arctic.

The aims of this project are to quantify the temporal variability of the oceanic circulation, heat and salt transports, water mass components, and eddy processes in the West Greenland boundary current system, and to determine the effects or atmospheric circulation and storms on the water exchange between the boundary current system and the open waters of the Labrador Basin. Results from this project will improve our understanding of the Atlantic Meridional Overturning Circulation (AMOC) which the West Greenland boundary current system is part of.

Changes in the strength of the AMOC investigated here can have crucial effects on the climate of adjacent countries and world-wide.

The project has four main scientific objectives that will be explored through a variety of data analysis techniques using the decade-long West Greenland mooring dataset from OSNAP. Context for the work will be given through analysis of upstream and downstream timeseries data provided also through OSNAP and by European collaborators. The four main objectives are: (1) to quantify the seasonal cycle and interannual variability of the circulation and water mass components of the West Greenland boundary current system, (2) to document the year-to-year changes in the dominant mesoscale processes in the boundary current – including the meandering/eddy formation and wind-driven upwelling – and assess the resulting impacts on shelf-basin exchange of heat and salt and, ultimately, on convection in the basin, (3) to characterize the atmospheric circulation and storm climate that drive the wind- driven exchange between the West Greenland shelf and Labrador Basin, and (4) to quantify observationally for the first time the transport, seasonal variation, and dominant mesoscale processes of the West Greenland Coastal Current.

This work, focused on the detailed processes and dynamics of the West Greenland boundary current system, will improve our understanding of the AMOC and its ramifications for climate. It will provide invaluable information for better interpreting the causes of AMOC variability and its links to freshwater discharge from the Arctic and Greenland as well as water mass transformation in the Labrador and Irminger Seas.

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.