The Role of Closed Gyres in Setting the Zonal Transport of the Antarctic Circumpolar Current

Eddy-permitting simulations are used to show that basinlike gyres can be observed in the large-scale barotropic flow of a wind-driven channel with a meridional topographic ridge. This is confirmed using both two-layer quasigeostrophic and 25-level primitive equation models at high horizontal resolut...

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Published in:Journal of Physical Oceanography
Main Authors: Nadeau, Louis-Philippe, Ferrari, Raffaele
Other Authors: Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Format: Article in Journal/Newspaper
Language:English
Published: American Meteorological Society 2015
Subjects:
Online Access:http://hdl.handle.net/1721.1/100785
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spelling ftmit:oai:dspace.mit.edu:1721.1/100785 2023-06-11T04:05:20+02:00 The Role of Closed Gyres in Setting the Zonal Transport of the Antarctic Circumpolar Current Nadeau, Louis-Philippe Ferrari, Raffaele Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Nadeau, Louis-Philippe Ferrari, Raffaele 2015-01 application/pdf http://hdl.handle.net/1721.1/100785 en_US eng American Meteorological Society http://dx.doi.org/10.1175/jpo-d-14-0173.1 Journal of Physical Oceanography 0022-3670 1520-0485 http://hdl.handle.net/1721.1/100785 Nadeau, Louis-Philippe, and Raffaele Ferrari. “The Role of Closed Gyres in Setting the Zonal Transport of the Antarctic Circumpolar Current.” Journal of Physical Oceanography 45, no. 6 (June 2015): 1491–1509. © 2015 American Meteorological Society orcid:0000-0002-3736-1956 Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. American Meteorological Society Article http://purl.org/eprint/type/JournalArticle 2015 ftmit https://doi.org/10.1175/jpo-d-14-0173.1 2023-05-29T08:26:39Z Eddy-permitting simulations are used to show that basinlike gyres can be observed in the large-scale barotropic flow of a wind-driven channel with a meridional topographic ridge. This is confirmed using both two-layer quasigeostrophic and 25-level primitive equation models at high horizontal resolution. Comparing results from simulations with and without the topographic ridge, it is shown that the zonal baroclinic transport in the channel increases with increasing wind stress when the bottom topography is flat but not when there is a meridional ridge. The saturation of transport for increasing wind occurs in conjunction with the development of recirculating gyres in the large-scale barotropic streamfunction. This suggests that the total circulation can be thought of as a superposition of a gyre mode (which has zero circumpolar transport) and a free circumpolar mode (which contains all of the transport). Basinlike gyres arise in the channel because the topography steers the barotropic streamlines and supports a frictional boundary layer similar to the more familiar ones observed along western boundaries. The gyre mode is thus closely linked with the bottom form stress exerted by the along-ridge flow and provides the sink for the wind momentum input. In this framework, any increase in wind forcing spins a stronger gyre as opposed to feeding the circumpolar transport. This hypothesis is supported with a suite of experiments where key parameters are carried over a wide range: wind stress, wind stress curl, ridge height, channel length, and bottom friction. Mathematics and Climate Research Network (Fellowship) National Science Foundation (U.S.) (Award OCE-1233832) Article in Journal/Newspaper Antarc* Antarctic DSpace@MIT (Massachusetts Institute of Technology) Antarctic The Antarctic Curl ENVELOPE(-63.071,-63.071,-70.797,-70.797) Journal of Physical Oceanography 45 6 1491 1509
institution Open Polar
collection DSpace@MIT (Massachusetts Institute of Technology)
op_collection_id ftmit
language English
description Eddy-permitting simulations are used to show that basinlike gyres can be observed in the large-scale barotropic flow of a wind-driven channel with a meridional topographic ridge. This is confirmed using both two-layer quasigeostrophic and 25-level primitive equation models at high horizontal resolution. Comparing results from simulations with and without the topographic ridge, it is shown that the zonal baroclinic transport in the channel increases with increasing wind stress when the bottom topography is flat but not when there is a meridional ridge. The saturation of transport for increasing wind occurs in conjunction with the development of recirculating gyres in the large-scale barotropic streamfunction. This suggests that the total circulation can be thought of as a superposition of a gyre mode (which has zero circumpolar transport) and a free circumpolar mode (which contains all of the transport). Basinlike gyres arise in the channel because the topography steers the barotropic streamlines and supports a frictional boundary layer similar to the more familiar ones observed along western boundaries. The gyre mode is thus closely linked with the bottom form stress exerted by the along-ridge flow and provides the sink for the wind momentum input. In this framework, any increase in wind forcing spins a stronger gyre as opposed to feeding the circumpolar transport. This hypothesis is supported with a suite of experiments where key parameters are carried over a wide range: wind stress, wind stress curl, ridge height, channel length, and bottom friction. Mathematics and Climate Research Network (Fellowship) National Science Foundation (U.S.) (Award OCE-1233832)
author2 Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Nadeau, Louis-Philippe
Ferrari, Raffaele
format Article in Journal/Newspaper
author Nadeau, Louis-Philippe
Ferrari, Raffaele
spellingShingle Nadeau, Louis-Philippe
Ferrari, Raffaele
The Role of Closed Gyres in Setting the Zonal Transport of the Antarctic Circumpolar Current
author_facet Nadeau, Louis-Philippe
Ferrari, Raffaele
author_sort Nadeau, Louis-Philippe
title The Role of Closed Gyres in Setting the Zonal Transport of the Antarctic Circumpolar Current
title_short The Role of Closed Gyres in Setting the Zonal Transport of the Antarctic Circumpolar Current
title_full The Role of Closed Gyres in Setting the Zonal Transport of the Antarctic Circumpolar Current
title_fullStr The Role of Closed Gyres in Setting the Zonal Transport of the Antarctic Circumpolar Current
title_full_unstemmed The Role of Closed Gyres in Setting the Zonal Transport of the Antarctic Circumpolar Current
title_sort role of closed gyres in setting the zonal transport of the antarctic circumpolar current
publisher American Meteorological Society
publishDate 2015
url http://hdl.handle.net/1721.1/100785
long_lat ENVELOPE(-63.071,-63.071,-70.797,-70.797)
geographic Antarctic
The Antarctic
Curl
geographic_facet Antarctic
The Antarctic
Curl
genre Antarc*
Antarctic
genre_facet Antarc*
Antarctic
op_source American Meteorological Society
op_relation http://dx.doi.org/10.1175/jpo-d-14-0173.1
Journal of Physical Oceanography
0022-3670
1520-0485
http://hdl.handle.net/1721.1/100785
Nadeau, Louis-Philippe, and Raffaele Ferrari. “The Role of Closed Gyres in Setting the Zonal Transport of the Antarctic Circumpolar Current.” Journal of Physical Oceanography 45, no. 6 (June 2015): 1491–1509. © 2015 American Meteorological Society
orcid:0000-0002-3736-1956
op_rights Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
op_doi https://doi.org/10.1175/jpo-d-14-0173.1
container_title Journal of Physical Oceanography
container_volume 45
container_issue 6
container_start_page 1491
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