Special Seminar: Predicting Processes of Dynamic Deformation across the Ocean Surface Why did oil in the Gulf of Mexico do what it did?
Abstract: Material deformation on the ocean surface is strongly governed by the underlying ocean dynamical processes ranging from mesoscale transport at O(100km), frontogenesis at O(10km), mixed layer instabilities at O(5km), submesoscale circulation at O(2km) and smaller features at O(500m) scale. In addition to the deformation effects, understanding the predictability of processes across this spectrum is critical and requires observations from satellite to in situ. Numerical models at resolutions of 3km, 1km, 250m and 50m sequentially represent the smaller scale processes that lead to the material deformation. The mesoscale transport produces large scale movement of material and is dominated primarily by stretching deformation. Frontogenesis driven by ocean eddies results in dilation deformation. Mesoscale eddies and eddy-driven frontogenesis are shown to be predictable given sufficient satellite observations. Mixed layer instabilities increase both the dilation and stretch at the ocean surface, and submesoscale features add significantly more deformation. Smaller scale features in the 50m model results show an upscale cascade from the small scale accumulating material into clumps which then move into the downwelling areas associated with fronts driven by the general circulation and ocean eddies.