Numerical Simulation of Drifter Response to Labrador Sea Convection

This report describes numerical simulation of two types of idealized drifters: pure Lagrangian drifters and the isobaric drifters. A large eddy (LES) model was used to predict the fully turbulent non-hydrostatic evolution of the oceanic flow fields that are typical of the Labrador Sea. The LES simulation indicates that either free or forced convection may dominate, depending upon the magnitudes of the wind stress and the net surface heat fluxed out of the ocean surface. Free convection predominates in the winter regimes of the periphery of the polar seas, especially in the very deeply convecting regions of open water adjacent to marginal ice zones. Forced convection is more dominant in the stable ice covered regions of the polar seas experiencing strong wind stirring and kinetic energy exchange with the ice. Forced convection may be an important precursor to free convection, and the organized cells of forced convection may help dilate the ice field to enhance heat and buoyancy exchange between the OPBL and the atmosphere.