Short-lived thorium isotopes (234Th, 228Th)
Repeated measurements of depth pro"les of 234Th (dissolved, 1}70 and ’70 lm particulate) at three stations (Orca, Minke, Sei) in the Ross Sea have been used to estimate the export of Th and particulate organic carbon (POC) from the euphotic zone. Sampling was carried out on three JGOFS cruises...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.483.2998 2023-05-15T17:53:35+02:00 Short-lived thorium isotopes (234Th, 228Th) In The Ross Sea Southern Ocean The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.483.2998 http://faculty.forestry.ubc.ca/hinch/cochran et al 2000.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.483.2998 http://faculty.forestry.ubc.ca/hinch/cochran et al 2000.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://faculty.forestry.ubc.ca/hinch/cochran et al 2000.pdf text ftciteseerx 2016-01-08T08:02:03Z Repeated measurements of depth pro"les of 234Th (dissolved, 1}70 and ’70 lm particulate) at three stations (Orca, Minke, Sei) in the Ross Sea have been used to estimate the export of Th and particulate organic carbon (POC) from the euphotic zone. Sampling was carried out on three JGOFS cruises covering the period from October 1996 (austral early spring) to April 1997 (austral fall). De"ciencies of 234Th relative to its parent 238U in the upper 100 m are small during the early spring cruise, increase to maximum values during the summer, and decrease over the course of the fall. Application of a non-steady-state model to the 234Th data shows that the #ux of Th from the euphotic zone occurs principally during the summer cruise and in the interval between summer and fall. Station Minke in the southwestern Ross Sea appears to sustain signi"cant 234Th removal for a longer period than is evident at Orca or Sei. Particulate 234Th activities and POC are greater in the 1}70 lm size fraction, except late in the summer cruise, when the ’70 lm POC fraction exceeds that of the 1}70 lm fraction. The POC/234Th ratio in the ’70 lm fraction exceeds that in the 1}70 lm fraction, likely due in part to the greater availability of surface sites for Th adsorption in the latter. Particulate 234Th #uxes are Text Orca Ross Sea Unknown Austral Ross Sea |
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Open Polar |
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ftciteseerx |
language |
English |
description |
Repeated measurements of depth pro"les of 234Th (dissolved, 1}70 and ’70 lm particulate) at three stations (Orca, Minke, Sei) in the Ross Sea have been used to estimate the export of Th and particulate organic carbon (POC) from the euphotic zone. Sampling was carried out on three JGOFS cruises covering the period from October 1996 (austral early spring) to April 1997 (austral fall). De"ciencies of 234Th relative to its parent 238U in the upper 100 m are small during the early spring cruise, increase to maximum values during the summer, and decrease over the course of the fall. Application of a non-steady-state model to the 234Th data shows that the #ux of Th from the euphotic zone occurs principally during the summer cruise and in the interval between summer and fall. Station Minke in the southwestern Ross Sea appears to sustain signi"cant 234Th removal for a longer period than is evident at Orca or Sei. Particulate 234Th activities and POC are greater in the 1}70 lm size fraction, except late in the summer cruise, when the ’70 lm POC fraction exceeds that of the 1}70 lm fraction. The POC/234Th ratio in the ’70 lm fraction exceeds that in the 1}70 lm fraction, likely due in part to the greater availability of surface sites for Th adsorption in the latter. Particulate 234Th #uxes are |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
In The Ross Sea Southern Ocean |
spellingShingle |
In The Ross Sea Southern Ocean Short-lived thorium isotopes (234Th, 228Th) |
author_facet |
In The Ross Sea Southern Ocean |
author_sort |
In The Ross Sea |
title |
Short-lived thorium isotopes (234Th, 228Th) |
title_short |
Short-lived thorium isotopes (234Th, 228Th) |
title_full |
Short-lived thorium isotopes (234Th, 228Th) |
title_fullStr |
Short-lived thorium isotopes (234Th, 228Th) |
title_full_unstemmed |
Short-lived thorium isotopes (234Th, 228Th) |
title_sort |
short-lived thorium isotopes (234th, 228th) |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.483.2998 http://faculty.forestry.ubc.ca/hinch/cochran et al 2000.pdf |
geographic |
Austral Ross Sea |
geographic_facet |
Austral Ross Sea |
genre |
Orca Ross Sea |
genre_facet |
Orca Ross Sea |
op_source |
http://faculty.forestry.ubc.ca/hinch/cochran et al 2000.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.483.2998 http://faculty.forestry.ubc.ca/hinch/cochran et al 2000.pdf |
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Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
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1766161292972785664 |