DOI: 10.1016/j.epsl.2020.116405
论文题名: Sea-ice control on deglacial lower cell circulation changes recorded by Drake Passage deep-sea corals
作者: Wilson D.J. ; Struve T. ; van de Flierdt T. ; Chen T. ; Li T. ; Burke A. ; Robinson L.F.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 544 语种: 英语
中文关键词: deep-sea corals
; deglaciation
; Drake Passage
; Nd isotopes
; ocean circulation
; sea-ice
英文关键词: Climate change
; Digital storage
; Glacial geology
; Ice control
; Isotopes
; Sea ice
; Antarctic cold reversals
; Circulation changes
; Deep-ocean circulation
; Global carbon cycle
; Last Glacial Maximum
; Nd isotopic compositions
; North Atlantic Deep Water
; Southwest Atlantic
; Oceanography
; coral
; deep water
; deglaciation
; Holocene
; ice retreat
; Last Glacial Maximum
; oceanic circulation
; sea ice
; Southern Ocean
; Anthozoa
英文摘要: The sequence of deep ocean circulation changes between the Last Glacial Maximum and the Holocene provides important insights for understanding deglacial climate change and the role of the deep ocean in the global carbon cycle. Although it is known that significant amounts of carbon were sequestered in a deep overturning cell during glacial periods and released during deglaciation, the driving mechanisms for these changes remain unresolved. Southern Ocean sea-ice has recently been proposed to play a critical role in setting the global deep ocean stratification and circulation, and hence carbon storage, but testing such conceptual and modelling studies requires data constraining past circulation changes. To this end, we present the first deglacial dataset of neodymium (Nd) isotopes measured on absolute-dated deep-sea corals from modern Lower Circumpolar Deep Water depths in the Drake Passage. Our record demonstrates deglacial variability of 2.5 εNd units, with radiogenic values of up to εNd=−5.9 during the Last Glacial Maximum providing evidence for a stratified glacial circulation mode with restricted incorporation of Nd from North Atlantic Deep Water in the lower cell. During the deglaciation, a renewed Atlantic influence in the deep Southern Ocean is recorded early in Heinrich Stadial 1, coincident with Antarctic sea-ice retreat, and is followed by a brief return to more Pacific-like values during the Antarctic Cold Reversal. These changes demonstrate a strong influence of Southern Ocean processes in setting deep ocean circulation and support the proposed sea-ice control on deep ocean structure. Furthermore, by constraining the Nd isotopic composition of Lower Circumpolar Deep Water in the Southern Ocean, our new data are important for interpreting deglacial circulation changes in other ocean basins and support a spatially asynchronous return of North Atlantic Deep Water to the deep southeast and southwest Atlantic Ocean. © 2020 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165347
Appears in Collections: 气候变化与战略
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作者单位: Institute of Earth and Planetary Sciences, University College London and Birkbeck, University of London, Gower Street, London, WC1E 6BT, United Kingdom; Department of Earth Science and Engineering, Imperial College London, London, SW7 2AZ, United Kingdom; Marine Isotope Geochemistry, Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, Carl-von-Ossietzky-Str. 9-11, Oldenburg, 26129, Germany; School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol, BS8 1RJ, United Kingdom; School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, China; School of Earth and Environmental Sciences, University of St Andrews, St Andrews, KY16 9AL, United Kingdom
Recommended Citation:
Wilson D.J.,Struve T.,van de Flierdt T.,et al. Sea-ice control on deglacial lower cell circulation changes recorded by Drake Passage deep-sea corals[J]. Earth and Planetary Science Letters,2020-01-01,544