Submesoscale Routes to Lateral Mixing in the Ocean

Long-Term Goals To determine whether lateral mixing at O1-10 km scales is due to a balanced or unbalanced downscale cascade from the mesoscale, or due to local vertical mixing by internal waves and surface forcing. Objectives Our work is testing hypothesis 3 of the white paper Scalable Lateral Mixing and Coherent Turbulence Non-QG, submesoscale instabilities feed a forward cascade of energy, scalar and Ertel PV variance, which enhances both isopycnal and diapycnal mixing. Related hypotheses are that submesoscale variability is associated with coherent structures and anisotropic mixing. Further, submesoscale processes are inherently vertical, as well as horizontal, and that submesoscale processes facilitate cross-front exchange.