The variability and dynamics of the Antartic Circumpolar Current south of Africa using proxy techniques
The general circulation of the Southern Ocean is dominated by the eastward flowing Antarctic Circumpolar Current (ACC). This is a continuous feature linking the three major ocean basins and thus forms a vital link in the transport of heat and salt on a global scale. These exchanges provide a vital m...
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Department of Oceanography
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ftunivcapetownir:oai:open.uct.ac.za:11427/38232 2024-09-15T17:45:22+00:00 The variability and dynamics of the Antartic Circumpolar Current south of Africa using proxy techniques Swart, Sebastiaan Ansorge, Isabelle J Speich, Sabrina Lutjeharms, Johann R. E. 2009 application/pdf http://hdl.handle.net/11427/38232 eng eng Department of Oceanography Faculty of Science http://hdl.handle.net/11427/38232 Physical Oceanography Doctoral Thesis Doctoral PhD 2009 ftunivcapetownir 2024-06-25T04:00:02Z The general circulation of the Southern Ocean is dominated by the eastward flowing Antarctic Circumpolar Current (ACC). This is a continuous feature linking the three major ocean basins and thus forms a vital link in the transport of heat and salt on a global scale. These exchanges provide a vital mechanism for the global thermohaline circulation (THC), which regulates the Earth's climate. In the high latitudes, where conditions are hostile, routine hydrographic observations are scarce resulting in a poor understanding of the physical and dynamic processes controlling the variability of the ACC and its influence on the THC. The GoodHope program launched in early 2004 aimed to establish an intensive monitoring platform that would provide detailed information on the physical structure and volume flux of water masses south of Africa. Sustained observations along the GoodHope cruise track provide the means to monitor the vertical structure and variability of the ACC and its associated fronts south of Africa. Such intense monitoring has been under way in the Drake Passage and south of Australia since the 1970s. A major objective of this thesis is to provide sound estimates of ACC transport and variability using both in situ measurements and remote sensing techniques. These estimates are crucial in understanding the role the ACC plays in the global thermohaline circulation (THC) and how the region south of Africa acts as a major conveyor of heat and salt to the higher latitudes. Baroclinic transports of the ACC, relative to 2500 dbar, are calculated from altimetry data alone. These transports agree with simultaneous observed estimates (rms difference in net transport is 5.2 Sv). These observations suggest that sea level anomalies largely reflect baroclinic transport variations above 2500 dbar. The transports contribution per ACC front shows that the SAF is responsible for the highest variability signals (>50%) even though its net transport contribution to the ACC was less (9%) than the APF. Furthermore, direct ... Doctoral or Postdoctoral Thesis Antarc* Antarctic antartic* Drake Passage Southern Ocean University of Cape Town: OpenUCT |
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Open Polar |
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University of Cape Town: OpenUCT |
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ftunivcapetownir |
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English |
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Physical Oceanography |
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Physical Oceanography Swart, Sebastiaan The variability and dynamics of the Antartic Circumpolar Current south of Africa using proxy techniques |
topic_facet |
Physical Oceanography |
description |
The general circulation of the Southern Ocean is dominated by the eastward flowing Antarctic Circumpolar Current (ACC). This is a continuous feature linking the three major ocean basins and thus forms a vital link in the transport of heat and salt on a global scale. These exchanges provide a vital mechanism for the global thermohaline circulation (THC), which regulates the Earth's climate. In the high latitudes, where conditions are hostile, routine hydrographic observations are scarce resulting in a poor understanding of the physical and dynamic processes controlling the variability of the ACC and its influence on the THC. The GoodHope program launched in early 2004 aimed to establish an intensive monitoring platform that would provide detailed information on the physical structure and volume flux of water masses south of Africa. Sustained observations along the GoodHope cruise track provide the means to monitor the vertical structure and variability of the ACC and its associated fronts south of Africa. Such intense monitoring has been under way in the Drake Passage and south of Australia since the 1970s. A major objective of this thesis is to provide sound estimates of ACC transport and variability using both in situ measurements and remote sensing techniques. These estimates are crucial in understanding the role the ACC plays in the global thermohaline circulation (THC) and how the region south of Africa acts as a major conveyor of heat and salt to the higher latitudes. Baroclinic transports of the ACC, relative to 2500 dbar, are calculated from altimetry data alone. These transports agree with simultaneous observed estimates (rms difference in net transport is 5.2 Sv). These observations suggest that sea level anomalies largely reflect baroclinic transport variations above 2500 dbar. The transports contribution per ACC front shows that the SAF is responsible for the highest variability signals (>50%) even though its net transport contribution to the ACC was less (9%) than the APF. Furthermore, direct ... |
author2 |
Ansorge, Isabelle J Speich, Sabrina Lutjeharms, Johann R. E. |
format |
Doctoral or Postdoctoral Thesis |
author |
Swart, Sebastiaan |
author_facet |
Swart, Sebastiaan |
author_sort |
Swart, Sebastiaan |
title |
The variability and dynamics of the Antartic Circumpolar Current south of Africa using proxy techniques |
title_short |
The variability and dynamics of the Antartic Circumpolar Current south of Africa using proxy techniques |
title_full |
The variability and dynamics of the Antartic Circumpolar Current south of Africa using proxy techniques |
title_fullStr |
The variability and dynamics of the Antartic Circumpolar Current south of Africa using proxy techniques |
title_full_unstemmed |
The variability and dynamics of the Antartic Circumpolar Current south of Africa using proxy techniques |
title_sort |
variability and dynamics of the antartic circumpolar current south of africa using proxy techniques |
publisher |
Department of Oceanography |
publishDate |
2009 |
url |
http://hdl.handle.net/11427/38232 |
genre |
Antarc* Antarctic antartic* Drake Passage Southern Ocean |
genre_facet |
Antarc* Antarctic antartic* Drake Passage Southern Ocean |
op_relation |
http://hdl.handle.net/11427/38232 |
_version_ |
1810493153185103872 |