How important are diapycnal mixing and geothermal heating for the deep circulation of the Western Mediterranean?

This is the authors' abstract. We don't add key points for this paper.

The dissipation rate of turbulent kinetic energy ε and the associated diapycnal turbulent mixing is inferred from a set of microstructure observations collected over several cruises from year 2012 to 2014. The geographical distribution of ε highlights several regions of enhanced levels of turbulence ranging from 10−9 to 10−6 W kg−1: the Sicily Channel, the Corsica Channel, and the Ligurian Sea. Elsewhere, ε was small, often below 10−10 W kg−1. Below 1300 m, geothermal heating provides three‐fold more buoyancy than small‐scale turbulence. Geothermal heating and turbulent diffusion provide enough buoyancy to balance 15% to 50% of a mean yearly deep water formation rate of 0.9 to 0.3 sverdrup (106 m3/s), respectively. The remaining part has to eventually overflow through the Strait of Gibraltar.