Labrador Sea
Interannual variations in the intermediate Labrador Sea Water are due largely to changes in convection throughout these periods. Weak convective periods are associated with more heat in the water column and deep convective periods are characterized by cold water. In the early 1990s, several consecutive severe winters contributed towards deep convection in the Labrador Sea. These winters were also associated with strong positive fluctuations in the North Atlantic Oscillation. Labrador Sea Water became very cold, fresh, and dense during this period, and the layer extended to depths of 2300m in the spring of 1994. Due to weakened convection, Labrador Sea Water began warming significantly and increased in salinity over the following decade. This trend continued through 2010 and 2011 when weak convection was observed in relation with negative North Atlantic Oscillation. Deep convection was observed again in 2012 with the Labrador Sea Water reaching 1400m, corresponding with a positive North Atlantic Oscillation similar to those seen in the early 1990s.