Enhanced mixing across the gyre boundary at the Gulf Stream front
| Type | : | ACL |
|---|---|---|
| Nature | : | Production scientifique |
| Au bénéfice du Laboratoire | : | Non |
| Statut de publication | : | Publié |
| Année de publication | : | 2020 |
| Auteurs (8) | : | WENEGRAT J,o THOMAS L SUNDERMEYER M,a TAYLOR Joe,d D'ASARO Eric KLYMAK Jody,m SHEARMAN R,k LEE C |
| Revue scientifique | : | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | : | 117 |
| Fascicule | : | 30 |
| Pages | : | 17607-17614 |
| DOI | : | 10.1073/pnas.2005558117 |
| URL | : | - |
| Abstract | : | The Gulf Stream front separates the North Atlantic subtropical and subpolar ocean gyres, water masses with distinct physical and bio-geochemical properties. Exchange across the front is believed to be necessary to balance the freshwater budget of the subtropi-cal gyre and to support the biological productivity of the region; however, the physical mechanisms responsible have been the sub-ject of long-standing debate. Here, the evolution of a passive dye released within the north wall of the Gulf Stream provides direct observational evidence of enhanced mixing across the Gulf Stream front. Numerical simulations indicate that the observed rapid cross-frontal mixing occurs via shear dispersion, generated by frontal instabilities and episodic vertical mixing. This provides unique direct evidence for the role of submesoscale fronts in gen-erating lateral mixing, a mechanism which has been hypothesized to be of general importance for setting the horizontal structure of the ocean mixed layer. Along the Gulf Stream front in the North Atlantic, these observations further suggest that shear dis-persion at sharp fronts may provide a source of freshwater flux large enough to explain much of the freshwater deficit in the subtropical-mode water budget and a flux of nutrients compara-ble to other mechanisms believed to control primary productivity in the subtropical gyre. |
| Mots-clés | : | CARBON; DISPERSION; GRADIENTS; Gulf Stream; NUTRIENTS; ocean mixing; oceanography; PARAMETERIZATION; submesoscale instabilities; WATER |
| Commentaire | : | Times Cited in Web of Science Core Collection: 9 |
| Tags | : | - |
| Fichier attaché | : | - |
| Citation | : |
Wenegrat JO, Thomas L, Sundermeyer MA, Taylor JD, D'Asaro E, Klymak JM, Shearman RK, Lee C (2020) Enhanced mixing across the gyre boundary at the Gulf Stream front. Proc Natl Acad Sci U S A 117: 17607-17614 | doi: 10.1073/pnas.2005558117
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