Deep-ocean mixing driven by small-scale internal tides
|Author(s)||Vic Clement1, 8, Naveira Garabato Alberto C.1, Green J. A. Mattias2, Waterhouse Amy F.3, Zhao Zhongxiang4, Melet Angelique5, de Lavergne Casimir6, Buijsman Maarten C.7, Stephenson Gordon R.7|
|Affiliation(s)||1 : Univ Southampton, Natl Oceanog Ctr, Ocean & Earth Sci, Southampton SO14 3ZH, Hants, England.
2 : Bangor Univ, Sch Ocean Sci, Menai Bridge LL57 2DG, Anglesey, Wales.
3 : Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92037 USA.
4 : Univ Washington, Appl Phys Lab, Seattle, WA 98105 USA.
5 : Mercator Ocean, F-31520 Ramonville St Agne, France.
6 : Sorbonne Univ, CNRS, MNHN, LOCEAN Lab,IRD, F-75005 Paris, France.
7 : Univ Southern Mississippi, Stennis Space Ctr, Hattiesburg, MS 39556 USA.
8 : LOPS, Plouzane, Bretagne, France.
|Source||Nature Communications (2041-1723) (Nature Publishing Group), 2019-05 , Vol. 10 , N. 2099 , P. 9p.|
|WOS© Times Cited||79|
Turbulent mixing in the ocean is key to regulate the transport of heat, freshwater and biogeochemical tracers, with strong implications for Earth's climate. In the deep ocean, tides supply much of the mechanical energy required to sustain mixing via the generation of internal waves, known as internal tides, whose fate-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 from an energetic viewpoint, small-scale internal tides, hitherto overlooked, account for the bulk (>50%) of global internal tide generation, breaking and mixing. Furthermore, we unveil the pronounced geographical variations of their energy proportion, ignored by current parameterisations of mixing in climate-scale models. 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 models.