The role of small-scale ocean mixing processes in regional sea surface temperature

The advances of numerical performances over the last decades have opened the way for km-scale climate modelling, which not only improve the representation of the state of the climate globally, but also allows to downscale climate information at a local scale where climate adaptation strategies are decided. In this context, it is interesting to evaluate the performance of such models at a regional scale.

In this study, we evaluate the capabilities of km-scale coupled climate simulations delivered by the EERIE (European Eddy-RIch Earth system models) project on the North Atlantic coastal shelfs in the representation of sea surface temperature and air surface temperature. Our findings suggest that eddy-rich coupled simulations can alleviate some of the large-scale biases found at coarser resolution but at the same time points out towards persistent model biases at local-scale due to unresolved or poorly parameterized mixing processes. We subsequently evaluate the nature and impact of unresolved oceanic mixing processes in climate models on the sea surface temperature mean state, variability and extremes.