Freshwater fluxes in the Labrador Sea

Lena Schulze, University of Southampton, Southampton, SO14, United Kingdom, Eleanor Frajka-Williams, University of Southampton, Southampton, United Kingdom and Sheldon Bacon, National Oceanography Centre, Southampton, United Kingdom
Abstract:
An ARGO-based heat and freshwater budget of the Labrador Sea shows a freshening of the surface waters (0-100 m) over the 2002-2011 period. Between the first and second 5-year period, observations indicate a gain of 40 cm of freshwater to the surface. As a site of deep water formation and wintertime deep convection, changes to the stratification in the Labrador Sea could have wide-reaching impacts. The surface freshening is comparable to past freshening periods associated with a reduction of deep convection (e.g. the Great Salinity Anomaly). However, the observed surface freshening is compensated by subsurface warming and salinifying (100 -2000 m) setting it apart from the past freshening periods.Using a Lagrangian approach, by tracking particles in a NEMO 1/12 degree ocean model, we examine where and when freshwater in the surface 30 m enter the basin. This will help determine what mechanisms control freshwater advection into the basin and how this exchange is related to forcing (e.g. winds) and dynamics (e.g. eddies).