The Antarctic drainage flow: implications for hemispheric flow on the Southern Hemisphere
An Ekman analysis of the surface drainage winds over a sloping ice surface is reported. Ekman pumping by the boundary layer leads to the formation of an upper tropospheric cyclonic vortex above the summit of the ice sheet. The strength and distribution of upper level vorticity is determined by the s...
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Cambridge University Press (CUP)
1989
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Online Access: | http://dx.doi.org/10.1017/s0954102089000404 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102089000404 |
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crcambridgeupr:10.1017/s0954102089000404 2024-03-03T08:37:36+00:00 The Antarctic drainage flow: implications for hemispheric flow on the Southern Hemisphere James, Ian N. 1989 http://dx.doi.org/10.1017/s0954102089000404 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102089000404 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Antarctic Science volume 1, issue 3, page 279-290 ISSN 0954-1020 1365-2079 Geology Ecology, Evolution, Behavior and Systematics Oceanography journal-article 1989 crcambridgeupr https://doi.org/10.1017/s0954102089000404 2024-02-08T08:36:58Z An Ekman analysis of the surface drainage winds over a sloping ice surface is reported. Ekman pumping by the boundary layer leads to the formation of an upper tropospheric cyclonic vortex above the summit of the ice sheet. The strength and distribution of upper level vorticity is determined by the shape of the underlying ice sheet. The calculation is verified by comparison with the results from a multi-level primitive equation model of flow above an axisymmetric ice sheet. Both models predict that the surface drainage flow will die out on a timescale of a few days, while the upper vortex is predicted to be considerably stronger than observed. Various mechanisms which could lead to the depletion of upper level vorticity, and hence to the retention of a substantial drainage flow, are discussed. It is concluded that disruption of the polar vortex by decaying mid-latitude cyclones, and the consequent export of cyclonic vorticity to lower latitudes, is the most probable mechanism. Article in Journal/Newspaper Antarc* Antarctic Antarctic Science Ice Sheet Cambridge University Press Antarctic The Antarctic Antarctic Science 1 3 279 290 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Geology Ecology, Evolution, Behavior and Systematics Oceanography |
spellingShingle |
Geology Ecology, Evolution, Behavior and Systematics Oceanography James, Ian N. The Antarctic drainage flow: implications for hemispheric flow on the Southern Hemisphere |
topic_facet |
Geology Ecology, Evolution, Behavior and Systematics Oceanography |
description |
An Ekman analysis of the surface drainage winds over a sloping ice surface is reported. Ekman pumping by the boundary layer leads to the formation of an upper tropospheric cyclonic vortex above the summit of the ice sheet. The strength and distribution of upper level vorticity is determined by the shape of the underlying ice sheet. The calculation is verified by comparison with the results from a multi-level primitive equation model of flow above an axisymmetric ice sheet. Both models predict that the surface drainage flow will die out on a timescale of a few days, while the upper vortex is predicted to be considerably stronger than observed. Various mechanisms which could lead to the depletion of upper level vorticity, and hence to the retention of a substantial drainage flow, are discussed. It is concluded that disruption of the polar vortex by decaying mid-latitude cyclones, and the consequent export of cyclonic vorticity to lower latitudes, is the most probable mechanism. |
format |
Article in Journal/Newspaper |
author |
James, Ian N. |
author_facet |
James, Ian N. |
author_sort |
James, Ian N. |
title |
The Antarctic drainage flow: implications for hemispheric flow on the Southern Hemisphere |
title_short |
The Antarctic drainage flow: implications for hemispheric flow on the Southern Hemisphere |
title_full |
The Antarctic drainage flow: implications for hemispheric flow on the Southern Hemisphere |
title_fullStr |
The Antarctic drainage flow: implications for hemispheric flow on the Southern Hemisphere |
title_full_unstemmed |
The Antarctic drainage flow: implications for hemispheric flow on the Southern Hemisphere |
title_sort |
antarctic drainage flow: implications for hemispheric flow on the southern hemisphere |
publisher |
Cambridge University Press (CUP) |
publishDate |
1989 |
url |
http://dx.doi.org/10.1017/s0954102089000404 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102089000404 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Antarctic Science Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctic Science Ice Sheet |
op_source |
Antarctic Science volume 1, issue 3, page 279-290 ISSN 0954-1020 1365-2079 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0954102089000404 |
container_title |
Antarctic Science |
container_volume |
1 |
container_issue |
3 |
container_start_page |
279 |
op_container_end_page |
290 |
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1792500064149569536 |