The impact of climate change on ocean submesoscale activity

As a case study we consider a region in the NE Atlantic under present and future climate conditions, using a time-slice method and global and nested regional ocean models. The high resolution regional model reproduces the strong seasonal cycle in submesoscale activity observed under present-day conditions.

Focusing on the well-resolved winter months, in the future, with a reduction in the MLD, there is a substantial reduction in submesoscale activity, an associated decrease in kinetic energy (KE) at the mesoscale, and the vertical buoyancy flux induced by submesoscale activity is reduced by a factor of 2. When submesoscale activity is suppressed, by increasing the parameterized lateral mixing in the model, the climate change induces a larger reduction in winter MLDs while there is less of a change in KE at the mesoscale.