Turbulent mixing in the ocean plays a key role in regulating the oceanic transport of heat, freshwater and biogeochemical tracers, with strong implications for Earth's climate. In the deep ocean, lunisolar tides have been shown to supply much of the mechanical energy required to sustain mixing via the generation of internal waves, known as internal tides. However, the fate of these internal tides -- the relative importance of their local versus remote breaking into turbulence -- remains uncertain. Here, we combine a semi-analytical model of internal tide generation with satellite and in situ measurements to show that small-scale internal tides, hitherto largely overlooked, account for the bulk (>70%) of global internal tide generation, breaking and mixing. Based on these results, we propose a physically consistent, observationally supported approach to accurately represent the dissipation of small-scale internal tides and their induced mixing in climate-scale ocean models.
Wednesday 26 September 2018 - 11:00 to 12:00
NOC Southampton - Node Room (074/02) (Waterfront Campus).