TY - JOUR
T1 - The residence time of Southern Ocean surface waters and the 100,000-year ice age cycle
AU - Hasenfratz, Adam P.
AU - Jaccard, Samuel L.
AU - Martínez-García, Alfredo
AU - Sigman, Daniel M.
AU - Hodell, David A.
AU - Vance, Derek
AU - Bernasconi, Stefano M.
AU - Kleiven, Helga F.
AU - Haumann, F. Alexander
AU - Haug, Gerald H.
N1 - Funding Information:
We thank U. Röhl, V. Lukies, and S. Steffer for technical support during the x-ray fluorescence analysis at MARUM; S. Bishop and M. Jaggi (ETH Zürich) and I. Mather (Cambridge) for technical assistance with the isotopic analysis; C. Archer, S. Westermann (ETH Zürich), and M. Greaves (Cambridge) for technical support with the trace metal analysis; T. Gordijn for helping with the sample preparation; and J. Gottschalk and J. Roberts for helpful discussions. Supported by ETH Research Grant ETH-04 11-1 (A.P.H.); Swiss National Science Foundation grants PP00P2_144811 and PP00P2_172915 (S.L.J.), PZ00P2_141424 (A.M.-G.), and 175162 (F.A.H.); the Max Planck Society (A.M.-G. and G.H.H.); and NSF grant OPP-1401489 and ExxonMobil through Princeton University’s Andlinger Center for Energy and the Environment (D.M.S.). Modern oxygen isotope sample collection by F.A.H. was supported by the BNP Paribas Foundation and ACE, which was a scientific expedition carried out under the auspices of the Swiss Polar Institute, supported by funding from the ACE Foundation and Ferring Pharmaceuticals. This research used sediment samples provided by the ODP, which is supported by NSF and participating countries under management of Joint Oceanographic Institutions (JOI) Inc.
Publisher Copyright:
2017 © The Authors, some rights reserved.
PY - 2019
Y1 - 2019
N2 - From 1.25 million to 700,000 years ago, the ice age cycle deepened and lengthened from 41,000- to 100,000-year periodicity, a transition that remains unexplained. Using surface- and bottom-dwelling foraminifera from the Antarctic Zone of the Southern Ocean to reconstruct the deep-to-surface supply of water during the ice ages of the past 1.5 million years, we found that a reduction in deep water supply and a concomitant freshening of the surface ocean coincided with the emergence of the high-amplitude 100,000-year glacial cycle. We propose that this slowing of deep-to-surface circulation (i.e., a longer residence time for Antarctic surface waters) prolonged ice ages by allowing the Antarctic halocline to strengthen, which increased the resistance of the Antarctic upper water column to orbitally paced drivers of carbon dioxide release.
AB - From 1.25 million to 700,000 years ago, the ice age cycle deepened and lengthened from 41,000- to 100,000-year periodicity, a transition that remains unexplained. Using surface- and bottom-dwelling foraminifera from the Antarctic Zone of the Southern Ocean to reconstruct the deep-to-surface supply of water during the ice ages of the past 1.5 million years, we found that a reduction in deep water supply and a concomitant freshening of the surface ocean coincided with the emergence of the high-amplitude 100,000-year glacial cycle. We propose that this slowing of deep-to-surface circulation (i.e., a longer residence time for Antarctic surface waters) prolonged ice ages by allowing the Antarctic halocline to strengthen, which increased the resistance of the Antarctic upper water column to orbitally paced drivers of carbon dioxide release.
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U2 - 10.1126/science.aat7067
DO - 10.1126/science.aat7067
M3 - Article
C2 - 30846597
AN - SCOPUS:85062636835
SN - 0036-8075
VL - 363
SP - 1080
EP - 1084
JO - Science
JF - Science
IS - 6431
ER -