Sources and sinks of upper-ocean submesoscale turbulence

Submesoscale eddies play a pivotal role in upper-ocean dynamics by influencing turbulent mixing and the advection of heat, energy, and tracers. In this study, we examine critical aspects of the submesoscale energy cycle using a novel configuration of the ICON-O ocean model. This setup employs grid refinement technology to achieve sub-kilometer resolution across a broad region of the North Atlantic. We analyze and quantify the key processes driving the generation and dissipation of submesoscale energy. Our findings reveal that baroclinic instability is the primary mechanism for submesoscale energy generation in the upper ocean. Substantial dissipation of this energy occurs via horizontal friction, indicating a downscale energy transfer. Finally, we explore strategies for parameterizing essential energy transformations and dissipation processes, highlighting their potential applications in coarser-resolution models that cannot explicitly resolve submesoscale dynamics.