An Annual Cycle of Submesoscale Vertical Flow and Restratification in the Upper Ocean
Numerical simulations suggest that submesoscale turbulence may transform lateral buoyancy gradients into vertical stratification and thus restratify the upper ocean via vertical flow. However, the observational evidence for this restratifying process has been lacking due to the difficulty in measuri...
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ftcaltechauth:oai:authors.library.caltech.edu:96358 2023-05-15T17:41:32+02:00 An Annual Cycle of Submesoscale Vertical Flow and Restratification in the Upper Ocean Yu, Xiaolong Naveira Garabato, Alberto C. Martin, Adrian P. Buckingham, Christian E. Brannigan, Liam Su, Zhan 2019-06 application/pdf https://authors.library.caltech.edu/96358/ https://authors.library.caltech.edu/96358/1/jpo-d-18-0253.1.pdf https://resolver.caltech.edu/CaltechAUTHORS:20190613-082314910 en eng American Meteorological Society https://authors.library.caltech.edu/96358/1/jpo-d-18-0253.1.pdf Yu, Xiaolong and Naveira Garabato, Alberto C. and Martin, Adrian P. and Buckingham, Christian E. and Brannigan, Liam and Su, Zhan (2019) An Annual Cycle of Submesoscale Vertical Flow and Restratification in the Upper Ocean. Journal of Physical Oceanography, 49 (6). pp. 1439-1461. ISSN 0022-3670. doi:10.1175/jpo-d-18-0253.1. https://resolver.caltech.edu/CaltechAUTHORS:20190613-082314910 <https://resolver.caltech.edu/CaltechAUTHORS:20190613-082314910> other Article PeerReviewed 2019 ftcaltechauth https://doi.org/10.1175/jpo-d-18-0253.1 2021-11-18T18:51:12Z Numerical simulations suggest that submesoscale turbulence may transform lateral buoyancy gradients into vertical stratification and thus restratify the upper ocean via vertical flow. However, the observational evidence for this restratifying process has been lacking due to the difficulty in measuring such ephemeral phenomena, particularly over periods of months to years. This study presents an annual cycle of the vertical velocity and associated restratification estimated from two nested clusters of meso- and submesoscale-resolving moorings, deployed in a typical midocean area of the northeast Atlantic. Vertical velocities inferred using the nondiffusive density equation are substantially stronger at submesoscales (horizontal scales of 1–10 km) than at mesoscales (horizontal scales of 10–100 km), with respective root-mean-square values of 38.0 ± 6.9 and 22.5 ± 3.3 m day^(−1). The largest submesoscale vertical velocities and rates of restratification occur in events of a few days’ duration in winter and spring, and extend down to at least 200 m below the mixed layer base. These events commonly coincide with the enhancement of submesoscale lateral buoyancy gradients, which is itself associated with persistent mesoscale frontogenesis. This suggests that mesoscale frontogenesis is a regular precursor of the submesoscale turbulence that restratifies the upper ocean. The upper-ocean restratification induced by submesoscale motions integrated over the annual cycle is comparable in magnitude to the net destratification driven by local atmospheric cooling, indicating that submesoscale flows play a significant role in determining the climatological upper-ocean stratification in the study area. Article in Journal/Newspaper Northeast Atlantic Caltech Authors (California Institute of Technology) Journal of Physical Oceanography 49 6 1439 1461 |
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Caltech Authors (California Institute of Technology) |
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English |
description |
Numerical simulations suggest that submesoscale turbulence may transform lateral buoyancy gradients into vertical stratification and thus restratify the upper ocean via vertical flow. However, the observational evidence for this restratifying process has been lacking due to the difficulty in measuring such ephemeral phenomena, particularly over periods of months to years. This study presents an annual cycle of the vertical velocity and associated restratification estimated from two nested clusters of meso- and submesoscale-resolving moorings, deployed in a typical midocean area of the northeast Atlantic. Vertical velocities inferred using the nondiffusive density equation are substantially stronger at submesoscales (horizontal scales of 1–10 km) than at mesoscales (horizontal scales of 10–100 km), with respective root-mean-square values of 38.0 ± 6.9 and 22.5 ± 3.3 m day^(−1). The largest submesoscale vertical velocities and rates of restratification occur in events of a few days’ duration in winter and spring, and extend down to at least 200 m below the mixed layer base. These events commonly coincide with the enhancement of submesoscale lateral buoyancy gradients, which is itself associated with persistent mesoscale frontogenesis. This suggests that mesoscale frontogenesis is a regular precursor of the submesoscale turbulence that restratifies the upper ocean. The upper-ocean restratification induced by submesoscale motions integrated over the annual cycle is comparable in magnitude to the net destratification driven by local atmospheric cooling, indicating that submesoscale flows play a significant role in determining the climatological upper-ocean stratification in the study area. |
format |
Article in Journal/Newspaper |
author |
Yu, Xiaolong Naveira Garabato, Alberto C. Martin, Adrian P. Buckingham, Christian E. Brannigan, Liam Su, Zhan |
spellingShingle |
Yu, Xiaolong Naveira Garabato, Alberto C. Martin, Adrian P. Buckingham, Christian E. Brannigan, Liam Su, Zhan An Annual Cycle of Submesoscale Vertical Flow and Restratification in the Upper Ocean |
author_facet |
Yu, Xiaolong Naveira Garabato, Alberto C. Martin, Adrian P. Buckingham, Christian E. Brannigan, Liam Su, Zhan |
author_sort |
Yu, Xiaolong |
title |
An Annual Cycle of Submesoscale Vertical Flow and Restratification in the Upper Ocean |
title_short |
An Annual Cycle of Submesoscale Vertical Flow and Restratification in the Upper Ocean |
title_full |
An Annual Cycle of Submesoscale Vertical Flow and Restratification in the Upper Ocean |
title_fullStr |
An Annual Cycle of Submesoscale Vertical Flow and Restratification in the Upper Ocean |
title_full_unstemmed |
An Annual Cycle of Submesoscale Vertical Flow and Restratification in the Upper Ocean |
title_sort |
annual cycle of submesoscale vertical flow and restratification in the upper ocean |
publisher |
American Meteorological Society |
publishDate |
2019 |
url |
https://authors.library.caltech.edu/96358/ https://authors.library.caltech.edu/96358/1/jpo-d-18-0253.1.pdf https://resolver.caltech.edu/CaltechAUTHORS:20190613-082314910 |
genre |
Northeast Atlantic |
genre_facet |
Northeast Atlantic |
op_relation |
https://authors.library.caltech.edu/96358/1/jpo-d-18-0253.1.pdf Yu, Xiaolong and Naveira Garabato, Alberto C. and Martin, Adrian P. and Buckingham, Christian E. and Brannigan, Liam and Su, Zhan (2019) An Annual Cycle of Submesoscale Vertical Flow and Restratification in the Upper Ocean. Journal of Physical Oceanography, 49 (6). pp. 1439-1461. ISSN 0022-3670. doi:10.1175/jpo-d-18-0253.1. https://resolver.caltech.edu/CaltechAUTHORS:20190613-082314910 <https://resolver.caltech.edu/CaltechAUTHORS:20190613-082314910> |
op_rights |
other |
op_doi |
https://doi.org/10.1175/jpo-d-18-0253.1 |
container_title |
Journal of Physical Oceanography |
container_volume |
49 |
container_issue |
6 |
container_start_page |
1439 |
op_container_end_page |
1461 |
_version_ |
1766143141848547328 |