Downstream propagation and remote dissipation of internal waves in the Southern Ocean
Recent microstructure observations in the Southern Ocean report enhanced internal gravity waves and turbulence in the frontal regions of the Antarctic Circumpolar Current extending a kilometer above rough bottom topography. Idealized numerical simulations and linear theory show that geostrophic flow...
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ftunivtasecite:oai:ecite.utas.edu.au:137675 2023-05-15T13:42:40+02:00 Downstream propagation and remote dissipation of internal waves in the Southern Ocean Zheng, K Nikurashin, M 2019 application/pdf https://doi.org/10.1175/JPO-D-18-0134.1 http://ecite.utas.edu.au/137675 en eng Amer Meteorological Soc http://ecite.utas.edu.au/137675/1/137675 - Downstream propagation and remote dissipation of internal waves in the Southern Ocean.pdf http://dx.doi.org/10.1175/JPO-D-18-0134.1 http://purl.org/au-research/grants/arc/DE150100937 Zheng, K and Nikurashin, M, Downstream propagation and remote dissipation of internal waves in the Southern Ocean, Journal of Physical Oceanography, 49 pp. 1873-1887. ISSN 0022-3670 (2019) [Refereed Article] http://ecite.utas.edu.au/137675 Engineering Fluid mechanics and thermal engineering Geophysical and environmental fluid flows Refereed Article PeerReviewed 2019 ftunivtasecite https://doi.org/10.1175/JPO-D-18-0134.1 2022-08-29T22:17:53Z Recent microstructure observations in the Southern Ocean report enhanced internal gravity waves and turbulence in the frontal regions of the Antarctic Circumpolar Current extending a kilometer above rough bottom topography. Idealized numerical simulations and linear theory show that geostrophic flows impinging on rough small-scale topography are very effective generators of internal waves and estimate vigorous wave radiation, breaking, and turbulence within a kilometer above bottom. However, both idealized simulations and linear theory assume periodic and spatially uniform topography and tend to overestimate the observed levels of turbulent energy dissipation locally at the generation sites. In this study, we explore the downstream evolution and remote dissipation of internal waves generated by geostrophic flows using a series of numerical, realistic topography simulations and parameters typical of Drake Passage. The results show that significant levels of internal wave kinetic energy and energy dissipation are present downstream of the rough topography, internal wave generation site. About 30% of the energy dissipation occurs locally over the rough topography region, where internal waves are generated. The rest of the energy dissipation takes place remotely and decays downstream of the generation site with an e-folding length scale of up to 2030 km. The model we use is two-dimensional with enhanced viscosity coefficients, and hence it can result in the underestimation of the remote wave dissipation and its decay length scale. The implications of our results for turbulent energy dissipation observations and mixing parameterizations are discussed. Article in Journal/Newspaper Antarc* Antarctic Drake Passage Southern Ocean eCite UTAS (University of Tasmania) Antarctic Southern Ocean The Antarctic Drake Passage Journal of Physical Oceanography 49 7 1873 1887 |
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Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Engineering Fluid mechanics and thermal engineering Geophysical and environmental fluid flows |
spellingShingle |
Engineering Fluid mechanics and thermal engineering Geophysical and environmental fluid flows Zheng, K Nikurashin, M Downstream propagation and remote dissipation of internal waves in the Southern Ocean |
topic_facet |
Engineering Fluid mechanics and thermal engineering Geophysical and environmental fluid flows |
description |
Recent microstructure observations in the Southern Ocean report enhanced internal gravity waves and turbulence in the frontal regions of the Antarctic Circumpolar Current extending a kilometer above rough bottom topography. Idealized numerical simulations and linear theory show that geostrophic flows impinging on rough small-scale topography are very effective generators of internal waves and estimate vigorous wave radiation, breaking, and turbulence within a kilometer above bottom. However, both idealized simulations and linear theory assume periodic and spatially uniform topography and tend to overestimate the observed levels of turbulent energy dissipation locally at the generation sites. In this study, we explore the downstream evolution and remote dissipation of internal waves generated by geostrophic flows using a series of numerical, realistic topography simulations and parameters typical of Drake Passage. The results show that significant levels of internal wave kinetic energy and energy dissipation are present downstream of the rough topography, internal wave generation site. About 30% of the energy dissipation occurs locally over the rough topography region, where internal waves are generated. The rest of the energy dissipation takes place remotely and decays downstream of the generation site with an e-folding length scale of up to 2030 km. The model we use is two-dimensional with enhanced viscosity coefficients, and hence it can result in the underestimation of the remote wave dissipation and its decay length scale. The implications of our results for turbulent energy dissipation observations and mixing parameterizations are discussed. |
format |
Article in Journal/Newspaper |
author |
Zheng, K Nikurashin, M |
author_facet |
Zheng, K Nikurashin, M |
author_sort |
Zheng, K |
title |
Downstream propagation and remote dissipation of internal waves in the Southern Ocean |
title_short |
Downstream propagation and remote dissipation of internal waves in the Southern Ocean |
title_full |
Downstream propagation and remote dissipation of internal waves in the Southern Ocean |
title_fullStr |
Downstream propagation and remote dissipation of internal waves in the Southern Ocean |
title_full_unstemmed |
Downstream propagation and remote dissipation of internal waves in the Southern Ocean |
title_sort |
downstream propagation and remote dissipation of internal waves in the southern ocean |
publisher |
Amer Meteorological Soc |
publishDate |
2019 |
url |
https://doi.org/10.1175/JPO-D-18-0134.1 http://ecite.utas.edu.au/137675 |
geographic |
Antarctic Southern Ocean The Antarctic Drake Passage |
geographic_facet |
Antarctic Southern Ocean The Antarctic Drake Passage |
genre |
Antarc* Antarctic Drake Passage Southern Ocean |
genre_facet |
Antarc* Antarctic Drake Passage Southern Ocean |
op_relation |
http://ecite.utas.edu.au/137675/1/137675 - Downstream propagation and remote dissipation of internal waves in the Southern Ocean.pdf http://dx.doi.org/10.1175/JPO-D-18-0134.1 http://purl.org/au-research/grants/arc/DE150100937 Zheng, K and Nikurashin, M, Downstream propagation and remote dissipation of internal waves in the Southern Ocean, Journal of Physical Oceanography, 49 pp. 1873-1887. ISSN 0022-3670 (2019) [Refereed Article] http://ecite.utas.edu.au/137675 |
op_doi |
https://doi.org/10.1175/JPO-D-18-0134.1 |
container_title |
Journal of Physical Oceanography |
container_volume |
49 |
container_issue |
7 |
container_start_page |
1873 |
op_container_end_page |
1887 |
_version_ |
1766171118493761536 |