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...
| Main Authors: | , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
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American Meteorological Society
2016
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| Online Access: | http://hdl.handle.net/1721.1/100785 https://orcid.org/0000-0002-3736-1956 |
| _version_ | 1811080736113950720 |
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| author | Nadeau, Louis-Philippe Ferrari, Raffaele |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Nadeau, Louis-Philippe Ferrari, Raffaele |
| author_sort | Nadeau, Louis-Philippe |
| collection | MIT |
| 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. |
| first_indexed | 2024-09-23T11:35:57Z |
| format | Article |
| id | mit-1721.1/100785 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T11:35:57Z |
| publishDate | 2016 |
| publisher | American Meteorological Society |
| record_format | dspace |
| spelling | mit-1721.1/1007852022-10-01T04:44:27Z 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 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) 2016-01-11T00:07:45Z 2016-01-11T00:07:45Z 2015-06 2015-01 Article http://purl.org/eprint/type/JournalArticle 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 https://orcid.org/0000-0002-3736-1956 en_US http://dx.doi.org/10.1175/jpo-d-14-0173.1 Journal of Physical Oceanography 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. application/pdf American Meteorological Society American Meteorological Society |
| spellingShingle | Nadeau, Louis-Philippe Ferrari, Raffaele The Role of Closed Gyres in Setting the Zonal Transport of the Antarctic Circumpolar Current |
| title | 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_short | 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 |
| url | http://hdl.handle.net/1721.1/100785 https://orcid.org/0000-0002-3736-1956 |
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