Antarctic Circumpolar Current (ACC) analysis of sediment core PS97/085-3 from POLARSTERN cruise PS97 (ANT-XXXI/3) in the Drake Passage


The Antarctic Circumpolar Current (ACC) plays a crucial role in global ocean circulation by fostering deep-water upwelling and formation of new water masses. On geological time-scales, ACC variations are poorly constrained beyond the last glacial. Here, we reconstruct changes in ACC strength in the central Drake Passage in vicinity of the modern Polar Front over a complete glacial-interglacial cycle (i.e., the past 140,000 years), based on sediment grain-size and geochemical characteristics. We found significant glacial-interglacial changes of ACC flow speed, with weakened current strength during glacials and a stronger circulation in interglacials. Superimposed on these orbital-scale changes are high-amplitude millennial-scale fluctuations, with ACC strength maxima correlating with diatom-based Antarctic winter sea-ice minima, particularly during full glacial conditions. We infer that the ACC is closely linked to Southern Hemisphere millennial-scale climate oscillations, amplified through Antarctic sea ice extent changes. These strong ACC variations modulated Pacific-Atlantic water exchange via the “cold water route” and potentially affected the Atlantic Meridional Overturning Circulation and marine carbon storage.

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Creator Wu, Shuzhuang ORCID logo; Lembke-Jene, Lester ORCID logo; Lamy, Frank ORCID logo; Arz, Helge Wolfgang ORCID logo; Nowaczyk, Norbert R; Xiao, Wenshen; Zhang, Xu ORCID logo; Hass, H Christian ORCID logo; Titschack, Jürgen ORCID logo; Zheng, Xufeng; Liu, Jiabo ORCID logo; Dumm, Levin; Diekmann, Bernhard ORCID logo; Nürnberg, Dirk; Tiedemann, Ralf ORCID logo; Kuhn, Gerhard ORCID logo
Publisher PANGAEA
Publication Year 2020
Rights Creative Commons Attribution 4.0 International;
OpenAccess true
Resource Type Bundled Publication of Datasets; Collection
Format application/zip
Size 6 datasets
Discipline Earth System Research
Spatial Coverage (-62.167 LON, -58.354 LAT)