Formation and export of dense shelf water from the Ade´lie Depression, East Antarctica
Coastal polynyas in the Adelie Depression are an important source of Antarctic Bottom Water to the Australian-Antarctic Basin. We present time series (April 1998 to May 1999 and August 1999 to February 2000) of data from temperature-salinity sensors, in both the Adelie Depression and the known outfl...
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ftunivtasmania:oai:eprints.utas.edu.au:6942 2023-05-15T13:36:46+02:00 Formation and export of dense shelf water from the Ade´lie Depression, East Antarctica Williams, GD Bindoff, NL Marsland, SJ Rintoul, SR 2008 application/pdf https://eprints.utas.edu.au/6942/ https://eprints.utas.edu.au/6942/1/Williams_Bindoff_etal_2008.pdf https://doi.org/10.1029/2007JC004346 en eng https://eprints.utas.edu.au/6942/1/Williams_Bindoff_etal_2008.pdf Williams, GD, Bindoff, NL, Marsland, SJ and Rintoul, SR 2008 , 'Formation and export of dense shelf water from the Ade´lie Depression, East Antarctica' , Journal of Geophysical Research, vol. 113, no. C04039 , doi:10.1029/2007JC004346 <http://dx.doi.org/10.1029/2007JC004346>. cc_utas 260403 Physical Oceanography polynya shelf water Article PeerReviewed 2008 ftunivtasmania https://doi.org/10.1029/2007JC004346 2020-05-30T07:20:49Z Coastal polynyas in the Adelie Depression are an important source of Antarctic Bottom Water to the Australian-Antarctic Basin. We present time series (April 1998 to May 1999 and August 1999 to February 2000) of data from temperature-salinity sensors, in both the Adelie Depression and the known outflow region of the Adelie Sill, to describe the annual cycle of shelf water densities. From April through September, salinification beneath the polynya produces dense shelf waters. During September–October, shelf water densities in the depression peak at 27.94 kg m3, and the cooling and freshening signature of Ice Shelf Water is observed north of Buchanan Bay. In November–December, shelf water densities decrease as intrusions of warm and relatively fresh modified Circumpolar Deep Water enter east of the Ade´lie Sill. From January–March the surface layer is conditioned by the cooling of the atmosphere, which overturns the upper water column. At the Ade´lie Sill, observed daily mean currents were approximately 10 cm s1 with intense instantaneous currents greater than 50 cm s1 at the sill depth. Using an idealized outflow region with a rectangular cross-sectional area (6 106 m2), we present the first estimates of shelf water export by potential density class. Assuming shelf water with a minimum density of 27.88 kg m3 has sufficient negative buoyancy for downslope mixing and a fourfold volume increase (1:3 mixing ratio) from entrainment, the dense shelf water export of 0.1–0.5 Sv results in an annual average production of bottom water in this region of between 0.4 and 2.0 Sv. The wide range in bottom water estimate results from data limitations, and a narrowing of this range requires further mooring observations. Article in Journal/Newspaper Antarc* Antarctic Antarctica Antarctica Journal Buchanan Bay East Antarctica Ice Shelf University of Tasmania: UTas ePrints Antarctic East Antarctica Australian Antarctic Basin ENVELOPE(120.000,120.000,-60.000,-60.000) Australian-Antarctic Basin ENVELOPE(134.115,134.115,-58.800,-58.800) Adelie Depression ENVELOPE(146.000,146.000,-67.417,-67.417) Buchanan Bay ENVELOPE(144.667,144.667,-67.083,-67.083) Journal of Geophysical Research 113 C4 |
institution |
Open Polar |
collection |
University of Tasmania: UTas ePrints |
op_collection_id |
ftunivtasmania |
language |
English |
topic |
260403 Physical Oceanography polynya shelf water |
spellingShingle |
260403 Physical Oceanography polynya shelf water Williams, GD Bindoff, NL Marsland, SJ Rintoul, SR Formation and export of dense shelf water from the Ade´lie Depression, East Antarctica |
topic_facet |
260403 Physical Oceanography polynya shelf water |
description |
Coastal polynyas in the Adelie Depression are an important source of Antarctic Bottom Water to the Australian-Antarctic Basin. We present time series (April 1998 to May 1999 and August 1999 to February 2000) of data from temperature-salinity sensors, in both the Adelie Depression and the known outflow region of the Adelie Sill, to describe the annual cycle of shelf water densities. From April through September, salinification beneath the polynya produces dense shelf waters. During September–October, shelf water densities in the depression peak at 27.94 kg m3, and the cooling and freshening signature of Ice Shelf Water is observed north of Buchanan Bay. In November–December, shelf water densities decrease as intrusions of warm and relatively fresh modified Circumpolar Deep Water enter east of the Ade´lie Sill. From January–March the surface layer is conditioned by the cooling of the atmosphere, which overturns the upper water column. At the Ade´lie Sill, observed daily mean currents were approximately 10 cm s1 with intense instantaneous currents greater than 50 cm s1 at the sill depth. Using an idealized outflow region with a rectangular cross-sectional area (6 106 m2), we present the first estimates of shelf water export by potential density class. Assuming shelf water with a minimum density of 27.88 kg m3 has sufficient negative buoyancy for downslope mixing and a fourfold volume increase (1:3 mixing ratio) from entrainment, the dense shelf water export of 0.1–0.5 Sv results in an annual average production of bottom water in this region of between 0.4 and 2.0 Sv. The wide range in bottom water estimate results from data limitations, and a narrowing of this range requires further mooring observations. |
format |
Article in Journal/Newspaper |
author |
Williams, GD Bindoff, NL Marsland, SJ Rintoul, SR |
author_facet |
Williams, GD Bindoff, NL Marsland, SJ Rintoul, SR |
author_sort |
Williams, GD |
title |
Formation and export of dense shelf water from the Ade´lie Depression, East Antarctica |
title_short |
Formation and export of dense shelf water from the Ade´lie Depression, East Antarctica |
title_full |
Formation and export of dense shelf water from the Ade´lie Depression, East Antarctica |
title_fullStr |
Formation and export of dense shelf water from the Ade´lie Depression, East Antarctica |
title_full_unstemmed |
Formation and export of dense shelf water from the Ade´lie Depression, East Antarctica |
title_sort |
formation and export of dense shelf water from the ade´lie depression, east antarctica |
publishDate |
2008 |
url |
https://eprints.utas.edu.au/6942/ https://eprints.utas.edu.au/6942/1/Williams_Bindoff_etal_2008.pdf https://doi.org/10.1029/2007JC004346 |
long_lat |
ENVELOPE(120.000,120.000,-60.000,-60.000) ENVELOPE(134.115,134.115,-58.800,-58.800) ENVELOPE(146.000,146.000,-67.417,-67.417) ENVELOPE(144.667,144.667,-67.083,-67.083) |
geographic |
Antarctic East Antarctica Australian Antarctic Basin Australian-Antarctic Basin Adelie Depression Buchanan Bay |
geographic_facet |
Antarctic East Antarctica Australian Antarctic Basin Australian-Antarctic Basin Adelie Depression Buchanan Bay |
genre |
Antarc* Antarctic Antarctica Antarctica Journal Buchanan Bay East Antarctica Ice Shelf |
genre_facet |
Antarc* Antarctic Antarctica Antarctica Journal Buchanan Bay East Antarctica Ice Shelf |
op_relation |
https://eprints.utas.edu.au/6942/1/Williams_Bindoff_etal_2008.pdf Williams, GD, Bindoff, NL, Marsland, SJ and Rintoul, SR 2008 , 'Formation and export of dense shelf water from the Ade´lie Depression, East Antarctica' , Journal of Geophysical Research, vol. 113, no. C04039 , doi:10.1029/2007JC004346 <http://dx.doi.org/10.1029/2007JC004346>. |
op_rights |
cc_utas |
op_doi |
https://doi.org/10.1029/2007JC004346 |
container_title |
Journal of Geophysical Research |
container_volume |
113 |
container_issue |
C4 |
_version_ |
1766083832646205440 |