Meridional circulation across the Antarctic Circumpolar Current serves as a double 231 Pa and 230 Th trap
Upwelling of Circumpolar Deep Water in the Weddell Gyre and low scavenging rates south of the Antarctic Circumpolar Current (ACC) cause an accumulation of particle reactive nuclides in the Weddell Gyre. A ventilation/reversible scavenging model that successfully described the accumulation of 230Th i...
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ftnioz:oai:imis.nioz.nl:282211 2023-05-15T13:47:57+02:00 Meridional circulation across the Antarctic Circumpolar Current serves as a double 231 Pa and 230 Th trap Rutgers van der Loeff, M. Venchiarutti, C. Stimac, I. van Ooijen, J. Huhn, O. Rohardt, G. Strass, V.H. 2016 http://imis.nioz.nl/imis.php?module=ref&refid=282211 en eng info:eu-repo/semantics/altIdentifier/wos/000386738200008 info:eu-repo/semantics/altIdentifier/doi/doi.org/10.1016/j.epsl.2016.07.027 http://imis.nioz.nl/imis.php?module=ref&refid=282211 info:eu-repo/semantics/closedAccess %3Ci%3EEarth+Planet.+Sci.+Lett.+455%3C%2Fi%3E%3A+73-84.+%3Ca+href%3D%22https%3A%2F%2Fdx.doi.org%2F10.1016%2Fj.epsl.2016.07.027%22+target%3D%22_blank%22%3Ehttps%3A%2F%2Fdx.doi.org%2F10.1016%2Fj.epsl.2016.07.027%3C%2Fa%3E info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2016 ftnioz https://doi.org/10.1016/j.epsl.2016.07.027 2022-05-01T14:04:44Z Upwelling of Circumpolar Deep Water in the Weddell Gyre and low scavenging rates south of the Antarctic Circumpolar Current (ACC) cause an accumulation of particle reactive nuclides in the Weddell Gyre. A ventilation/reversible scavenging model that successfully described the accumulation of 230Th in this area was tested with other particle reactive nuclides and failed to adequately describe the depth-distributions of 231Pa and 210Pb. We present here a modified model that includes a nutrient-like accumulation south of the Antarctic Polar Front in an upper meridional circulation cell, as well as transport to a deep circulation cell in the Weddell Gyre by scavenging and subsequent release at depth. The model also explains depletion of 231Pa and 230Th in Weddell Sea Bottom Water (WSBW) by ventilation of newly formed deep water on a timescale of 10 years, but this water mass is too dense to leave the Weddell Gyre.In order to quantify the processes responsible for the 231Pa-and 230Th-composition of newly formed Antarctic Bottom Water (AABW) we present a mass balance of 231Pa and 230Th in the Atlantic sector of the Southern Ocean based on new data from the GEOTRACES program. The ACC receives 6.0 ±1.5 ×106dpms−1of 230Th from the Weddell Sea, similar in magnitude to the net input of 4.2 ±3.0 ×106dpms−1from the north. For 231Pa, the relative contribution from the Weddell Sea is much smaller, only 0.3 ±0.1 ×106, compared to 2.7 ±1.4 ×106dpms−1from the north. Weddell Sea Deep Water (WSDW) leaving the Weddell Gyre northward to form AABW is exposed in the ACC to resuspended opal-rich sediments that act as efficient scavengers with a Th/Pa fractionation factor F ≤1. Hydrothermal inputs may provide additional removal with low F. Scavenging in the full meridional circulation acros Article in Journal/Newspaper Antarc* Antarctic Southern Ocean Weddell Sea NIOZ Repository (Royal Netherlands Institute for Sea Research) Antarctic Southern Ocean The Antarctic Weddell Weddell Sea Earth and Planetary Science Letters 455 73 84 |
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Open Polar |
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NIOZ Repository (Royal Netherlands Institute for Sea Research) |
op_collection_id |
ftnioz |
language |
English |
description |
Upwelling of Circumpolar Deep Water in the Weddell Gyre and low scavenging rates south of the Antarctic Circumpolar Current (ACC) cause an accumulation of particle reactive nuclides in the Weddell Gyre. A ventilation/reversible scavenging model that successfully described the accumulation of 230Th in this area was tested with other particle reactive nuclides and failed to adequately describe the depth-distributions of 231Pa and 210Pb. We present here a modified model that includes a nutrient-like accumulation south of the Antarctic Polar Front in an upper meridional circulation cell, as well as transport to a deep circulation cell in the Weddell Gyre by scavenging and subsequent release at depth. The model also explains depletion of 231Pa and 230Th in Weddell Sea Bottom Water (WSBW) by ventilation of newly formed deep water on a timescale of 10 years, but this water mass is too dense to leave the Weddell Gyre.In order to quantify the processes responsible for the 231Pa-and 230Th-composition of newly formed Antarctic Bottom Water (AABW) we present a mass balance of 231Pa and 230Th in the Atlantic sector of the Southern Ocean based on new data from the GEOTRACES program. The ACC receives 6.0 ±1.5 ×106dpms−1of 230Th from the Weddell Sea, similar in magnitude to the net input of 4.2 ±3.0 ×106dpms−1from the north. For 231Pa, the relative contribution from the Weddell Sea is much smaller, only 0.3 ±0.1 ×106, compared to 2.7 ±1.4 ×106dpms−1from the north. Weddell Sea Deep Water (WSDW) leaving the Weddell Gyre northward to form AABW is exposed in the ACC to resuspended opal-rich sediments that act as efficient scavengers with a Th/Pa fractionation factor F ≤1. Hydrothermal inputs may provide additional removal with low F. Scavenging in the full meridional circulation acros |
format |
Article in Journal/Newspaper |
author |
Rutgers van der Loeff, M. Venchiarutti, C. Stimac, I. van Ooijen, J. Huhn, O. Rohardt, G. Strass, V.H. |
spellingShingle |
Rutgers van der Loeff, M. Venchiarutti, C. Stimac, I. van Ooijen, J. Huhn, O. Rohardt, G. Strass, V.H. Meridional circulation across the Antarctic Circumpolar Current serves as a double 231 Pa and 230 Th trap |
author_facet |
Rutgers van der Loeff, M. Venchiarutti, C. Stimac, I. van Ooijen, J. Huhn, O. Rohardt, G. Strass, V.H. |
author_sort |
Rutgers van der Loeff, M. |
title |
Meridional circulation across the Antarctic Circumpolar Current serves as a double 231 Pa and 230 Th trap |
title_short |
Meridional circulation across the Antarctic Circumpolar Current serves as a double 231 Pa and 230 Th trap |
title_full |
Meridional circulation across the Antarctic Circumpolar Current serves as a double 231 Pa and 230 Th trap |
title_fullStr |
Meridional circulation across the Antarctic Circumpolar Current serves as a double 231 Pa and 230 Th trap |
title_full_unstemmed |
Meridional circulation across the Antarctic Circumpolar Current serves as a double 231 Pa and 230 Th trap |
title_sort |
meridional circulation across the antarctic circumpolar current serves as a double 231 pa and 230 th trap |
publishDate |
2016 |
url |
http://imis.nioz.nl/imis.php?module=ref&refid=282211 |
geographic |
Antarctic Southern Ocean The Antarctic Weddell Weddell Sea |
geographic_facet |
Antarctic Southern Ocean The Antarctic Weddell Weddell Sea |
genre |
Antarc* Antarctic Southern Ocean Weddell Sea |
genre_facet |
Antarc* Antarctic Southern Ocean Weddell Sea |
op_source |
%3Ci%3EEarth+Planet.+Sci.+Lett.+455%3C%2Fi%3E%3A+73-84.+%3Ca+href%3D%22https%3A%2F%2Fdx.doi.org%2F10.1016%2Fj.epsl.2016.07.027%22+target%3D%22_blank%22%3Ehttps%3A%2F%2Fdx.doi.org%2F10.1016%2Fj.epsl.2016.07.027%3C%2Fa%3E |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/000386738200008 info:eu-repo/semantics/altIdentifier/doi/doi.org/10.1016/j.epsl.2016.07.027 http://imis.nioz.nl/imis.php?module=ref&refid=282211 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1016/j.epsl.2016.07.027 |
container_title |
Earth and Planetary Science Letters |
container_volume |
455 |
container_start_page |
73 |
op_container_end_page |
84 |
_version_ |
1766248046871445504 |