The influence of subglacial discharge on the oceanic fate of meltwater from the Greenland ice sheet

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This study concentrates on the influence that melt waters from Greenland fjords has on the circulation of the Labrador Sea to determine the fate of the melt water to the North Atlantic Ocean. The premise of the proposal is that fresh water discharged from glaciers and trapped below the ocean’s surface on East Greenland has different fate from the fresh water that reaches the surface. The difference in destination between surface and subsurface fresh waters is because the wind should drive surface waters distinctly from subsurface waters, which are more isolated from the wind forcing. The study will be carried out with computer model simulations and satellite data. Findings from this study should have implications for global scale models that study water sinking in the North Atlantic and its impact on climate. The project will support one graduate student and will organize a workshop on climate processes for math & science teachers in Georgia.This project will investigate transport processes in the Labrador Sea, from areas of direct influence of Greenland ice sheet melt water to areas in the Labrador Sea where deep convection occurs in winter. The goal of the proposal is to identify and quantify the effect of subglacial discharge on transport pathways in the Labrador Sea. The hypothesis is that subsurface melt water from East Greenland’s fjords will be transported to the Labrador Sea more effectively than surface melt water. If this hypothesis is proven accurate, then it will show that the correct depiction of fjord circulation is essential for representation of large-scale circulation and convection in ocean models. The proposal also hypothesizes that, with global warming, outflow plumes will either a) be more influenced by winds off W Greenland and reduce transport of melt water into central Labrador Sea, or b) increase flow instabilities and spatial variability that will increase transport into central Labrador Sea. Satellite observations and model simulations will quantify the relative importance of the two possible outcomes of the latter hypothesis and the effects of melt water on winter convection. The work is justified by the need to represent subglacial discharge on eastern Greenland, in contrast to the surface input of land-terminating glaciers on West Greenland. As Broader Impacts, the project will support one grad student and one research scientist, partially. The PIs will organize a 1-day workshop on climate processes for math & science teachers, as part of Georgia’s Long Term Ecological Research.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.