Radionuclides in the water column at stations near the Antarctic Polar Front in the South Atlantic ...

Vertical profiles of dissolved and particulate 230Th and 231Pa were obtained across the Antarctic Circumpolar Current (ACC) in the southern Atlantic. North of the Polar Front, dissolved and total 230Th increase with depth in conformity with published scavenging models. There is no depletion of 230Th...

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Bibliographic Details
Main Authors: Rutgers van der Loeff, Michiel M, Berger, Gijs W
Format: Article in Journal/Newspaper
Language:English
Published: PANGAEA 1993
Subjects:
Online Access:https://dx.doi.org/10.1594/pangaea.730453
https://doi.pangaea.de/10.1594/PANGAEA.730453
Description
Summary:Vertical profiles of dissolved and particulate 230Th and 231Pa were obtained across the Antarctic Circumpolar Current (ACC) in the southern Atlantic. North of the Polar Front, dissolved and total 230Th increase with depth in conformity with published scavenging models. There is no depletion of 230Th or 231Pa in the water column south of the Polar Front, thought to be an area of enhanced biological productivity. 230Th concentrations increase three-fold to the Weddell Sea across the ACC. Dissolved and total 231Pa concentrations are relatively constant below 500 m depth at about 0.3 dpm m**-3, and change little with depth or latitude. The results from the Weddell Gyre are explained by a mixing-scavenging model that takes into account the input of lower Circumpolar Deep Water through upwelling, which is the main source of water in the Weddell Gyre and is enriched in 230Th but not in 231Pa. 230Th accumulates in the Weddell Gyre as a result of a reduction in the scavenging rate and by ingrowth from 234U. Ingrowth ... : Supplement to: Rutgers van der Loeff, Michiel M; Berger, Gijs W (1993): Scavenging of 230Th and 231Pa near the antarctic polar front in the South Atlantic. Deep Sea Research Part I: Oceanographic Research Papers, 40(2), 339-357 ...