Lagrangian Studies of Lateral Mixing
Technical Report,01 Jan 2009,31 Dec 2015
University of Washington Seattle United States
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The Lateral Mixing Experiment LATMIX focused on mixing and stirring at the submesocales 100 m to 10 km in the upper ocean. LATMIX1 targeted the Sargasso Sea, southeast of the Gulf Stream, aiming for a region with relatively weak mesoscale eddy activity and clear waters to focus on submesoscale stirring by internal wave shear dispersion and finescale vorticity anomalies. LATMIX2 targeted the wintertime Gulf Stream, where deep mixed layers, strong lateral density gradients Gulf Stream north wall and the high probability of encountering intense atmospheric forcing provided ideal conditions for observing the generation and evolution of submesoscale instabilities. A towed profiler was used to conduct synoptic, 4D surveys to resolve submesoscale variability. Results include finding that iinteractions between near inertial internal waves and symmetric instability enhance dissipation at submesocale fronts, ii vertical vorticity in the wintertime mixed layer south of the Gulf Stream exhibits statistics, including skew, that are consistent with existing numerical predictions and iii Nearly flat salinity gradient spectra observed in the Sargasso Sea taken along isopycnal surfaces can be explained by internal wave horizontal strain at low horizontal wavenumbers, but not for shorter-scale variability.
- Physical and Dynamic Oceanography