Amplification of the divergent component from balanced motions and forward kinetic energy cascade in an ocean-atmosphere simulation

Accurately representing ocean motions and their respective cross-scale interactions enhances climate models’ predictions. This study investigates how kinetic energy (KE) cascades respond to atmospheric forcing resolution in a coupled ocean-atmosphere simulation (COAS). By comparing this simulation with another with the same oceanic configuration but with a different atmospheric forcing resolution, we found that high-frequency wind fluctuations and a deeper mixed layer in COAS increased the population of small scale oceanic motions, thus strengthening the forward KE cascade. Our analysis, which included a partition into balanced motions and non-balanced motions, further revealed that the high frequency of the divergent component of submesoscale balanced motions from COAS is primarily responsible for amplifying the forward KE cascade.