This study examines the Gulf Stream energy cycle, with emphasis on the submesoscale pathway relative to other energy sinks. Using a high-resolution coupled air-sea simulation (CROCO-WRF), we construct a Lorenz diagram based on submesoscale and background energy budgets, defined through temporal and spatial scale separation. We found that submesoscale energy mainly flows from potential energy (PE), via eddy stirring and subsequent baroclinic conversion. A significant portion of the submesoscale kinetic energy (KE) production is dissipated by surface vertical mixing. A forward KE cascade occurs only in the unbalanced submesoscale range (eddy scale < 10 km), while balanced submesoscales resemble mesoscales in their energy cycle but are driven by surface processes. Overall, interior dissipation is less effective at removing mesoscale KE than surface and bottom friction, though it plays a major role in reducing mesoscale PE. These insights have implications for the parameterizations required in intermediate-resolution models for future climate simulations.
Contreras et al. (Fri,) studied this question.