An Annual Cycle of Submesoscale Vertical Flow and Restratification in the Upper OceanSource: Journal of Physical Oceanography:;2019:;volume 049:;issue 006::page 1439Author:Yu, Xiaolong
,
Naveira Garabato, Alberto C.
,
Martin, Adrian P.
,
Buckingham, Christian E.
,
Brannigan, Liam
,
Su, Zhan
DOI: 10.1175/JPO-D-18-0253.1Publisher: American Meteorological Society
Abstract: AbstractNumerical 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.
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contributor author | Yu, Xiaolong | |
contributor author | Naveira Garabato, Alberto C. | |
contributor author | Martin, Adrian P. | |
contributor author | Buckingham, Christian E. | |
contributor author | Brannigan, Liam | |
contributor author | Su, Zhan | |
date accessioned | 2019-10-05T06:48:25Z | |
date available | 2019-10-05T06:48:25Z | |
date copyright | 4/8/2019 12:00:00 AM | |
date issued | 2019 | |
identifier other | JPO-D-18-0253.1.pdf | |
identifier uri | http://yetl.yabesh.ir/yetl1/handle/yetl/4263475 | |
description abstract | AbstractNumerical 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. | |
publisher | American Meteorological Society | |
title | An Annual Cycle of Submesoscale Vertical Flow and Restratification in the Upper Ocean | |
type | Journal Paper | |
journal volume | 49 | |
journal issue | 6 | |
journal title | Journal of Physical Oceanography | |
identifier doi | 10.1175/JPO-D-18-0253.1 | |
journal fristpage | 1439 | |
journal lastpage | 1461 | |
tree | Journal of Physical Oceanography:;2019:;volume 049:;issue 006 | |
contenttype | Fulltext |