A Description of Local and Nonlocal Eddy-Mean Flow Interaction in a Global Eddying State Estimate

Carl I Wunsch1,2, Ru Chen3 and Glenn Flierl1, (1)Massachusetts Institute of Technology, Cambridge, MA, United States, (2)Harvard University, Cambridge, MA, United States, (3)Scripps Institution of Oceanography, La Jolla, CA, United States
Abstract:
The assumption that local baroclinic instability dominates eddy-mean flow interactions is tested on a global scale using a dynamically consistent eddying state estimate. Interactions are divided into local and nonlocal. If all the energy released from the mean flow through eddy-mean flow interaction is used to support eddy growth in the same region, or if all the energy released from eddies through eddy-mean flow interaction is used to feed back to the mean flow in the same region, eddy-mean flow interaction is local; otherwise, it is nonlocal. Different regions have different characters: in the subtropical region studied in detail, interactions are dominantly local. In the Southern Ocean and Kuroshio and Gulf Stream Extension regions, they are mainly nonlocal. Geographical variability of dominant eddy-eddy, and eddy-mean flow processes is a dominant factor in understanding ocean energetics. This work points out the prevalence of eddy energy nonlocality and indicates the need of using nonlocal eddy parameterization schemes.
Back to: Ocean Submesoscale Processes and Potential Scientific Breakthrough: Simulations, Observations, and Applications I Posters