Vertical flow in the Southern Ocean estimated from individual moorings
Vertical flow in the Southern Ocean estimated from individual moorings
In this study, we demonstrate that oceanic vertical velocities can be estimated from individual mooring measurements, even for non-stationary flow. This result is obtained under three assumptions: i. weak diffusion (Péclet number ?1), ii. weak friction (Reynolds number ?1), and iii. small inertial terms (Rossby number ?1). The theoretical framework is applied to a set of 4 moorings located in the Southern Ocean. For this site, the diagnosed vertical velocities are highly variable in time, their standard deviation being one-to-two orders of magnitude greater than their mean. We demonstrate that the time-averaged vertical velocities are largely induced by geostrophic flow, and can be estimated from the time-averaged density and horizontal velocities. This suggests that local time-mean vertical velocities are primarily forced by the time-mean ocean dynamics, rather than by e.g. transient eddies or internal waves. We also show that, in the context of these four moorings, the time-mean vertical flow is consistent with stratified Taylor column dynamics in the presence of a topographic obstacle.
Geographic location/entity, Southern Ocean, Circulation/ Dynamics, Vertical motion, Observational techniques and algorithms, Buoy observations
2209-2220
Sévellec, F.
01569d6c-65b0-4270-af2a-35b0a77c9140
Naveira Garabato, A.C.
97c0e923-f076-4b38-b89b-938e11cea7a6
Brearley, J.A.
91ab83c7-8d07-4b93-acbf-16ee4a6cdfe5
Sheen, K.L.
11fc9ce4-1a9a-4925-ae04-816e5e8660ae
September 2015
Sévellec, F.
01569d6c-65b0-4270-af2a-35b0a77c9140
Naveira Garabato, A.C.
97c0e923-f076-4b38-b89b-938e11cea7a6
Brearley, J.A.
91ab83c7-8d07-4b93-acbf-16ee4a6cdfe5
Sheen, K.L.
11fc9ce4-1a9a-4925-ae04-816e5e8660ae
Sévellec, F., Naveira Garabato, A.C., Brearley, J.A. and Sheen, K.L.
(2015)
Vertical flow in the Southern Ocean estimated from individual moorings.
Journal of Physical Oceanography, 45 (9), .
(doi:10.1175/JPO-D-14-0065.1).
Abstract
In this study, we demonstrate that oceanic vertical velocities can be estimated from individual mooring measurements, even for non-stationary flow. This result is obtained under three assumptions: i. weak diffusion (Péclet number ?1), ii. weak friction (Reynolds number ?1), and iii. small inertial terms (Rossby number ?1). The theoretical framework is applied to a set of 4 moorings located in the Southern Ocean. For this site, the diagnosed vertical velocities are highly variable in time, their standard deviation being one-to-two orders of magnitude greater than their mean. We demonstrate that the time-averaged vertical velocities are largely induced by geostrophic flow, and can be estimated from the time-averaged density and horizontal velocities. This suggests that local time-mean vertical velocities are primarily forced by the time-mean ocean dynamics, rather than by e.g. transient eddies or internal waves. We also show that, in the context of these four moorings, the time-mean vertical flow is consistent with stratified Taylor column dynamics in the presence of a topographic obstacle.
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jpo-d-14-0065%2E1.pdf
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e-pub ahead of print date: July 2015
Published date: September 2015
Keywords:
Geographic location/entity, Southern Ocean, Circulation/ Dynamics, Vertical motion, Observational techniques and algorithms, Buoy observations
Organisations:
Physical Oceanography
Identifiers
Local EPrints ID: 378815
URI: http://eprints.soton.ac.uk/id/eprint/378815
ISSN: 0022-3670
PURE UUID: ec9cec2e-b17a-4ffc-b4d2-c204ce2ad18e
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Date deposited: 07 Jul 2015 13:09
Last modified: 15 Mar 2024 03:24
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Author:
J.A. Brearley
Author:
K.L. Sheen
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