KINEMATIC SUBDUCTION RATE OF LABRADOR SEA WATER

The Labrador Sea (LS) is one of few places where the atmosphere has a direct impact on the deep ocean. During strong winters, the heat loss at the surface of Labrador Sea preconditions the cooling process, disrupts the stratified water column, producing a uniformly denser water mass. This process is called deep convection and is characterized by the production of Labrador Sea Water(LSW), which in turn contributes, from a larger scale, to the lower limb of the Meridional Overturning Circulation (MOC). Due to higher anthropogenic activities, resulting in a warmer environment, freshwater input (e.g. Greenland runoff, sea­ice melting, etc.) in the LS has increased in the past decades. This has a strong impact on the ocean ventilation as it restratifies the water column and prevents the convection process.The mixed layer at the surface of the ocean is often considered as an interface between the atmosphere and the deep ocean. In the LS, the depth of the mixed layer (MLD) is greatly affected by the seasonal cycle, the freshwater input, and local processes such as the deep convection. A way to study the ventilation process in the LS is to use a kinematic approach to calculate the subduction rate, which is the vertical transport of a water mass from the mixed layer into the permanent thermocline.In this study, we present our results on the subduction rate for a different range of LSW, using the Nucleus for European Modelling of the Ocean (NEMO) numerical model.