We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Orbital- and millennial-scale Antarctic Circumpolar Current variability in Drake Passage over the past 140,000 years.
- Authors
Wu, Shuzhuang; Lembke-Jene, Lester; Lamy, Frank; Arz, Helge W.; Nowaczyk, Norbert; Xiao, Wenshen; Zhang, Xu; Hass, H. Christian; Titschack, Jürgen; Zheng, Xufeng; Liu, Jiabo; Dumm, Levin; Diekmann, Bernhard; Nürnberg, Dirk; Tiedemann, Ralf; Kuhn, Gerhard
- Abstract
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. How the Antarctic Circumpolar Current (ACC) changed on glacial-interglacial time scales is not well known. Here, the authors present a 140,000 year long sediment record from the Drake passage and show both glacial-interglacial as well as millennial-scale variability which are linked to Atlantic variability and marine carbon storage.
- Subjects
ANTARCTIC Circumpolar Current; MERIDIONAL overturning circulation; WATER masses; SEA ice; OCEAN circulation; ANTARCTIC ice
- Publication
Nature Communications, 2021, Vol 12, Issue 1, p1
- ISSN
2041-1723
- Publication type
Article
- DOI
10.1038/s41467-021-24264-9