Investigation of the Impacts of Greenland Ice Sheet Melting on the along-Shelf Flow on Greenland Shelves and the Labrador Sea Deep Convection

Gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) satellite measuring system show that Greenland is losing mass as water is lost to the ocean. Past work has suggested that the freshwater flux from Greenland, particularly along the southeastern coast, may be affecting the Labrador Sea deep convection, a major driver of the world deep ocean circulation. The main objectives of this thesis are to examine (1) the relationship between Greenland freshwater flux and the near-surface Labrador Sea salinity; (2) the response of the Greenland shelf water flow to the freshwater flux from the coast; and (3) to predict when the Labrador Sea deep convection will shut down because of the near-surface Labrador Sea freshening. Using the GRACE results and analysis of Argo float hydrographic data showed that there is a strong correlation between the anomalous annual freshwater flux onto the southeastern Greenland shelf and the freshening of the Labrador Sea several months later. The corresponding regression coefficient is physically reasonable and the delay in freshening is what you would expect based on eddy propagation from the west Greenland coast to the site of Labrador Sea deep convection. Satellite altimeter data was used to estimate the interannual shelf water flow, but the flow trend was too small to be determined. Calculations of the heat flux during winter in the Labrador Sea region of deep convection showed that if the freshening continues at the present rate, in about 31 years the cooling heat flux in water will not be able to overcome the freshwater near-surface buoyancy and deep convection will cease.