Impact of Changing Boundary Current Properties on Deep Water Formation in the Central Labrador Sea

The stratification in the water column above the Labrador Sea Water layer in the central Labrador Sea is set by the properties of its boundary currents. The top part is fresh and (in winter) cold water of Arctic origin, while the subsurface layer contains warm and saline water of subtropical Atlantic origin. The buoyancy stored in these layers is determined by their T/S properties and is a primary factor in determining the occurrence of deep water formation and the properties of the water mass formed. The characteristics of both source regions of these boundary currents are, however, changing rapidly and are projected to change further in the coming decades. Using a 1D mixed layer model and analysis of three recent year-round data sets of hydrographic observations, we analyze how anomalies in the boundary current characteristics have impacted the mixed layer depth and properties in the recent past, and make projections for how changes in the boundary current properties are likely to affect them in the future.