Environmental Science and Engineering Seminar

For the first time, we explicitly resolve ocean turbulence down to ~10km in the global ocean using a novel high-resolution global model. Results highlight strong ubiquitous submesoscale turbulence (with scales ≲0.5º, i.e. ~50km at mid-latitude) in most oceans. These submesoscale structures, due to its nature of releasing potential energy into kinetic energy, cause strong upgradient (upward) vertical heat fluxes of 100-1000 W/m² in the upper ocean. Globally, submesoscale processes cause ~3 Petawatts (i.e. 3×10¹⁵ Watts) upward heat flux across 200m depth, which significantly influences the air-sea heat exchange. This may influence the ocean heat uptake from the atmosphere and also influence the mean ocean state. Furthermore, submesoscale dynamics is found to provide an important kinetic energy source that powers the global ocean circulation.