Lagrangian Studies of Lateral Mixing and an Internal Modeling and Observational Study of Three-Dimensional Upper Ocean Boundary Layer Dynamics and Parameterizations

摘要

Existing high-resolution regional models typically resolve the mean vertical structure of the upper ocean boundary layer. Physically-based parameterizations of vertical fluxes make it possible to account for subgrid mixing at length scales smaller than the layer depth, but no specialized parameterization is used to represent the dynamics of horizontal mixing below the O(1)km - O(10)km resolution scale. We aim to determine the physical limitations of subgrid parameterization on these scales. These projects address the following questions: * What physics govern horizontal and vertical mixing in the presence of horizontal variability on the 1-10 km scale; * What is the relative importance of horizontal and vertical mixing in determining the structure of the boundary layer; * What physics should be included to improve parameterizations; These projects continue the analysis of the 2006 and 2007 AESOP and fund preparations for the 2011 and 2012 Lateral Mixing experiments. During AESOP, Lee and D'Asaro pioneered an innovative approach to measuring submesoscale structure in strong fronts. An adaptive measurement program employed acoustically-tracked, neutrally-buoyant Lagrangian floats and a towed, undulating profiler to investigate the relative importance of vertical and horizontal mixing in governing boundary layer structure in the presence of O(1 km) scale horizontal variability. Remotely sensed sea surface temperature and ocean color, combined with rapid, high-resolution towed surveys and model results, guide float deployments to key locations within fronts.