Mesoscale Variability in the Labrador Sea

Abstract

Abstract : My long-term objective is to understand how deep convection, induced by strong buoyancy forcing at the ocean surface, influences the ocean circulation through convective plumes and geostrophic eddies. My immediate objective is to understand the interactions between convection and mesoscale circulation, in order to quantify the influence of convective events on the large scale circulation. Such interactions include: (a) The lateral mixing generated by baroclinic instability and geostrophic eddy interactions. How efficient are lateral mixing processes in convective regions? Can these processes account for the relatively homogeneous water mass found in the Labrador Sea in spring, in contrast to the highly spatially variable winter convection observed? (b) The formation and persistence of isolated chimneys of convected fluid. Observations reveal isolated cores of dense fluid with distinct water mass properties many months after convection ceases. How do such isolated cores persist despite the homogenization hypothesized above? (c) The tracer variability. What are the mechanisms responsible for generation of tracer variability observed on a variety of scales in the Labrador Sea? Are plumes or eddies more effective at generating variability? How is tracer variability dissipated following convection? (d) Float signatures of mesoscale eddies in convection regions. How are isobaric float statistics influenced by the presence of a convective mesoscale eddy eld? What are the float signatures of the eddies and the plumes?