Global scale-transfer of the ocean's kinetic energy and the role of the atmosphere

Our understanding of the ocean’s spatial scales and their coupling has been derived mostly from Fourier analysis in small "representative" regions, typically a few hundred kilometers in size, that cannot capture the vast dynamic range at planetary scales. Using commutative coarse-graining, we were recently able to provide the first estimate for the ocean's global scale transfer of kinetic energy (KE), across scales from 10 to 40,000 km. The analysis revealed energy exchanges between gyre-scales and mesoscales mediated by the atmospheric circulation via the "piston-effect," which is a mesoscale-gyrescale-atmosphere pathway that was missing from theories of the global ocean-atmosphere circulation.