The Impact of Finite-Amplitude Bottom Topography on Internal Wave Generation in the Southern Ocean
Direct observations in the Southern Ocean report enhanced internal wave activity and turbulence in a kilometer-thick layer above rough bottom topography collocated with the deep-reaching fronts of the Antarctic Circumpolar Current. Linear theory, corrected for finite-amplitude topography based on id...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | en_US |
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American Meteorological Society
2015
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| Online Access: | http://hdl.handle.net/1721.1/96954 https://orcid.org/0000-0002-3736-1956 |
| _version_ | 1811089055453020160 |
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| author | Nikurashin, Maxim Anatolevich Ferrari, Raffaele Grisouard, Nicolas Polzin, Kurt |
| 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 Nikurashin, Maxim Anatolevich Ferrari, Raffaele Grisouard, Nicolas Polzin, Kurt |
| author_sort | Nikurashin, Maxim Anatolevich |
| collection | MIT |
| description | Direct observations in the Southern Ocean report enhanced internal wave activity and turbulence in a kilometer-thick layer above rough bottom topography collocated with the deep-reaching fronts of the Antarctic Circumpolar Current. Linear theory, corrected for finite-amplitude topography based on idealized, two-dimensional numerical simulations, has been recently used to estimate the global distribution of internal wave generation by oceanic currents and eddies. The global estimate shows that the topographic wave generation is a significant sink of energy for geostrophic flows and a source of energy for turbulent mixing in the deep ocean. However, comparison with recent observations from the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean shows that the linear theory predictions and idealized two-dimensional simulations grossly overestimate the observed levels of turbulent energy dissipation. This study presents two- and three-dimensional, realistic topography simulations of internal lee-wave generation from a steady flow interacting with topography with parameters typical of Drake Passage. The results demonstrate that internal wave generation at three-dimensional, finite bottom topography is reduced compared to the two-dimensional case. The reduction is primarily associated with finite-amplitude bottom topography effects that suppress vertical motions and thus reduce the amplitude of the internal waves radiated from topography. The implication of these results for the global lee-wave generation is discussed. |
| first_indexed | 2024-09-23T14:13:04Z |
| format | Article |
| id | mit-1721.1/96954 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T14:13:04Z |
| publishDate | 2015 |
| publisher | American Meteorological Society |
| record_format | dspace |
| spelling | mit-1721.1/969542022-09-28T19:15:31Z The Impact of Finite-Amplitude Bottom Topography on Internal Wave Generation in the Southern Ocean Nikurashin, Maxim Anatolevich Ferrari, Raffaele Grisouard, Nicolas Polzin, Kurt Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Ferrari, Raffaele Direct observations in the Southern Ocean report enhanced internal wave activity and turbulence in a kilometer-thick layer above rough bottom topography collocated with the deep-reaching fronts of the Antarctic Circumpolar Current. Linear theory, corrected for finite-amplitude topography based on idealized, two-dimensional numerical simulations, has been recently used to estimate the global distribution of internal wave generation by oceanic currents and eddies. The global estimate shows that the topographic wave generation is a significant sink of energy for geostrophic flows and a source of energy for turbulent mixing in the deep ocean. However, comparison with recent observations from the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean shows that the linear theory predictions and idealized two-dimensional simulations grossly overestimate the observed levels of turbulent energy dissipation. This study presents two- and three-dimensional, realistic topography simulations of internal lee-wave generation from a steady flow interacting with topography with parameters typical of Drake Passage. The results demonstrate that internal wave generation at three-dimensional, finite bottom topography is reduced compared to the two-dimensional case. The reduction is primarily associated with finite-amplitude bottom topography effects that suppress vertical motions and thus reduce the amplitude of the internal waves radiated from topography. The implication of these results for the global lee-wave generation is discussed. National Science Foundation (U.S.) (Award CMG-1024198) 2015-05-11T14:24:33Z 2015-05-11T14:24:33Z 2014-11 2014-08 Article http://purl.org/eprint/type/JournalArticle 0022-3670 1520-0485 http://hdl.handle.net/1721.1/96954 Nikurashin, Maxim, Raffaele Ferrari, Nicolas Grisouard, and Kurt Polzin. “The Impact of Finite-Amplitude Bottom Topography on Internal Wave Generation in the Southern Ocean.” J. Phys. Oceanogr. 44, no. 11 (November 2014): 2938–2950. © 2014 American Meteorological Society https://orcid.org/0000-0002-3736-1956 en_US http://dx.doi.org/10.1175/jpo-d-13-0201.1 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 | Nikurashin, Maxim Anatolevich Ferrari, Raffaele Grisouard, Nicolas Polzin, Kurt The Impact of Finite-Amplitude Bottom Topography on Internal Wave Generation in the Southern Ocean |
| title | The Impact of Finite-Amplitude Bottom Topography on Internal Wave Generation in the Southern Ocean |
| title_full | The Impact of Finite-Amplitude Bottom Topography on Internal Wave Generation in the Southern Ocean |
| title_fullStr | The Impact of Finite-Amplitude Bottom Topography on Internal Wave Generation in the Southern Ocean |
| title_full_unstemmed | The Impact of Finite-Amplitude Bottom Topography on Internal Wave Generation in the Southern Ocean |
| title_short | The Impact of Finite-Amplitude Bottom Topography on Internal Wave Generation in the Southern Ocean |
| title_sort | impact of finite amplitude bottom topography on internal wave generation in the southern ocean |
| url | http://hdl.handle.net/1721.1/96954 https://orcid.org/0000-0002-3736-1956 |
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