Persistent export of 231Pa from the deep central Arctic Ocean over the past 35,000 years ...

• Main Authors: Hoffmann, Sharon S., McManus, Jerry F., Curry, William B., Brown-Ledger, L. Susan
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Columbia University 2013
• Subjects: Environmental sciences; Ecology; FOS: Biological sciences; Oceanography; FOS: Earth and related environmental sciences; Arctic; Arctic Ocean; Sea ice
• Online Access: https://dx.doi.org/10.7916/d8dz0kbx; https://academiccommons.columbia.edu/doi/10.7916/D8DZ0KBX

The Arctic Ocean has an important role in Earth’s climate, both through surface processes such as sea-ice formation and transport, and through the production and export of waters at depth that contribute to the global thermohaline circulation. Deciphering the deep Arctic Ocean’s palaeo-oceanographic history is a crucial part of understanding its role in climatic change. Here we show that sedimentary ratios of the radionuclides thorium-230 (230Th) and protactinium-231 (231Pa), which are produced in sea water and removed by particle scavenging on timescales of decades to centuries, respectively, record consistent evidence for the export of 231Pa from the deep Arctic and may indicate continuous deep-water exchange between the Arctic and Atlantic oceans throughout the past 35,000 years. Seven well-dated box-core records provide a comprehensive overview of 231Pa and 230Th burial in Arctic sediments during glacial, deglacial and interglacial conditions. Sedimentary 231Pa/230Th ratios decrease nearly linearly with ...