Thorium isotopes in the water column in Amundsen Basin during POLARSTERN cruises PS70 (ARK-XXII/2) in 2007 and PS94 (ARK-XXIX/3) in 2015

• Main Authors: Valk, Ole, Rutgers van der Loeff, Michiel M, Geibert, Walter, Gdaniec, Sandra, Moran, S Bradley, Lepore, Kate, Edwards, R Lawrence, Lu, Y, Puigcorbé, Viena, Casacuberta, Nuria, Paffrath, Ronja, Smethie, William, Roy-Barman, Matthieu
• Format: Other/Unknown Material
• Language: English
• Published: PANGAEA 2019
• Subjects: 230Th; Arctic Ocean; AWI_MarGeoChem; GEOTRACES; Global marine biogeochemical cycles of trace elements and their isotopes; Marine Geochemistry @ AWI; Time series; amundsen basin; Barents Sea
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.908068; https://doi.org/10.1594/PANGAEA.908068

In this study we present dissolved ²³⁰Th and ²³²Th results, as well as amount of particulate ²³⁴Th from total ²³⁴Th. The data, obtained as part of the GEOTRACES central Arctic Ocean sections GN04 (2015) and IPY11 (2007). Samples were analyzed following GEOTRACES methods, and compared to previous results from 1991. We observe significant decreases in ²³⁰Th concentrations in the intermediate waters of the Amundsen Basin. This removal was explained by scavenging removal of dissolved ²³⁰Th on the Barents Sea Shelf and along Atlantic water inflow pathways. This finding shows that a far-field decrease of dissolved ²³⁰Th can be caused by changes in scavenging on inflow passages and highlights the importance of repeated GEOTRACES sections.