A Microscale View of Mixing and Overturning across the Antarctic Circumpolar Current
The relative roles of isoneutral stirring by mesoscale eddies and dianeutral stirring by small-scale turbulence in setting the large-scale temperature–salinity relation of the Southern Ocean against the action of the overturning circulation are assessed by analyzing a set of shear and temperature mi...
| Main Authors: | , , , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
American Meteorological Society
2017
|
| Online Access: | http://hdl.handle.net/1721.1/108339 https://orcid.org/0000-0002-3736-1956 |
| _version_ | 1811083498292772864 |
|---|---|
| author | Naveira Garabato, Alberto C. Polzin, Kurt L. Ferrari, Raffaele Zika, Jan D. Forryan, Alexander |
| 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 Naveira Garabato, Alberto C. Polzin, Kurt L. Ferrari, Raffaele Zika, Jan D. Forryan, Alexander |
| author_sort | Naveira Garabato, Alberto C. |
| collection | MIT |
| description | The relative roles of isoneutral stirring by mesoscale eddies and dianeutral stirring by small-scale turbulence in setting the large-scale temperature–salinity relation of the Southern Ocean against the action of the overturning circulation are assessed by analyzing a set of shear and temperature microstructure measurements across Drake Passage in a “triple decomposition” framework. It is shown that a picture of mixing and overturning across a region of the Antarctic Circumpolar Current (ACC) may be constructed from a relatively modest number of microstructure profiles. The rates of isoneutral and dianeutral stirring are found to exhibit distinct, characteristic, and abrupt variations: most notably, a one to two orders of magnitude suppression of isoneutral stirring in the upper kilometer of the ACC frontal jets and an order of magnitude intensification of dianeutral stirring in the subpycnocline and deepest layers of the ACC. These variations balance an overturning circulation with meridional flows of O(1) mm s⁻¹ across the ACC’s mean thermohaline structure. Isoneutral and dianeutral stirring play complementary roles in balancing the overturning, with isoneutral processes dominating in intermediate waters and the Upper Circumpolar Deep Water and dianeutral processes prevailing in lighter and denser layers. |
| first_indexed | 2024-09-23T12:34:01Z |
| format | Article |
| id | mit-1721.1/108339 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T12:34:01Z |
| publishDate | 2017 |
| publisher | American Meteorological Society |
| record_format | dspace |
| spelling | mit-1721.1/1083392022-10-01T09:49:31Z A Microscale View of Mixing and Overturning across the Antarctic Circumpolar Current Naveira Garabato, Alberto C. Polzin, Kurt L. Ferrari, Raffaele Zika, Jan D. Forryan, Alexander Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Ferrari, Raffaele The relative roles of isoneutral stirring by mesoscale eddies and dianeutral stirring by small-scale turbulence in setting the large-scale temperature–salinity relation of the Southern Ocean against the action of the overturning circulation are assessed by analyzing a set of shear and temperature microstructure measurements across Drake Passage in a “triple decomposition” framework. It is shown that a picture of mixing and overturning across a region of the Antarctic Circumpolar Current (ACC) may be constructed from a relatively modest number of microstructure profiles. The rates of isoneutral and dianeutral stirring are found to exhibit distinct, characteristic, and abrupt variations: most notably, a one to two orders of magnitude suppression of isoneutral stirring in the upper kilometer of the ACC frontal jets and an order of magnitude intensification of dianeutral stirring in the subpycnocline and deepest layers of the ACC. These variations balance an overturning circulation with meridional flows of O(1) mm s⁻¹ across the ACC’s mean thermohaline structure. Isoneutral and dianeutral stirring play complementary roles in balancing the overturning, with isoneutral processes dominating in intermediate waters and the Upper Circumpolar Deep Water and dianeutral processes prevailing in lighter and denser layers. 2017-04-21T15:21:09Z 2017-04-21T15:21:09Z 2016-01 2015-02 Article http://purl.org/eprint/type/JournalArticle 0022-3670 1520-0485 http://hdl.handle.net/1721.1/108339 Naveira Garabato, Alberto C.; Polzin, Kurt L.; Ferrari, Raffaele; Zika, Jan D. and Forryan, Alexander. “A Microscale View of Mixing and Overturning Across the Antarctic Circumpolar Current.” Journal of Physical Oceanography 46, no. 1 (January 2016): 233–254. © American Meteorological Society https://orcid.org/0000-0002-3736-1956 en_US http://dx.doi.org/10.1175/jpo-d-15-0025.1 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 | Naveira Garabato, Alberto C. Polzin, Kurt L. Ferrari, Raffaele Zika, Jan D. Forryan, Alexander A Microscale View of Mixing and Overturning across the Antarctic Circumpolar Current |
| title | A Microscale View of Mixing and Overturning across the Antarctic Circumpolar Current |
| title_full | A Microscale View of Mixing and Overturning across the Antarctic Circumpolar Current |
| title_fullStr | A Microscale View of Mixing and Overturning across the Antarctic Circumpolar Current |
| title_full_unstemmed | A Microscale View of Mixing and Overturning across the Antarctic Circumpolar Current |
| title_short | A Microscale View of Mixing and Overturning across the Antarctic Circumpolar Current |
| title_sort | microscale view of mixing and overturning across the antarctic circumpolar current |
| url | http://hdl.handle.net/1721.1/108339 https://orcid.org/0000-0002-3736-1956 |
| work_keys_str_mv | AT naveiragarabatoalbertoc amicroscaleviewofmixingandoverturningacrosstheantarcticcircumpolarcurrent AT polzinkurtl amicroscaleviewofmixingandoverturningacrosstheantarcticcircumpolarcurrent AT ferrariraffaele amicroscaleviewofmixingandoverturningacrosstheantarcticcircumpolarcurrent AT zikajand amicroscaleviewofmixingandoverturningacrosstheantarcticcircumpolarcurrent AT forryanalexander amicroscaleviewofmixingandoverturningacrosstheantarcticcircumpolarcurrent AT naveiragarabatoalbertoc microscaleviewofmixingandoverturningacrosstheantarcticcircumpolarcurrent AT polzinkurtl microscaleviewofmixingandoverturningacrosstheantarcticcircumpolarcurrent AT ferrariraffaele microscaleviewofmixingandoverturningacrosstheantarcticcircumpolarcurrent AT zikajand microscaleviewofmixingandoverturningacrosstheantarcticcircumpolarcurrent AT forryanalexander microscaleviewofmixingandoverturningacrosstheantarcticcircumpolarcurrent |