气候变化领域集成服务门户(CCPortal): Coupled Southern Ocean cooling and Antarctic ice sheet expansion during the middle Miocene

CCPortal

DOI	10.1038/s41561-020-0623-0
	Coupled Southern Ocean cooling and Antarctic ice sheet expansion during the middle Miocene
	Leutert T.J.; Auderset A.; Martínez-García A.; Modestou S.; Meckler A.N.
发表日期	2020
ISSN	17520894
起始页码	634
结束页码	639
卷号	13 期号:9
英文摘要	The middle Miocene climate transition (~14 million years ago) was characterized by a dramatic increase in the volume of the Antarctic ice sheet. The driving mechanism of this transition remains under discussion, with hypotheses including circulation changes, declining carbon dioxide in the atmosphere and orbital forcing. Southern Ocean records of planktic foraminiferal Mg/Ca have previously been interpreted to indicate a cooling of 6–7 °C and a decrease in salinity that preceded Antarctic cryosphere expansion by up to ~300,000 years. This interpretation has led to the hypothesis that changes in meridional heat and vapour transport along with an early thermal isolation of Antarctica from extrapolar climates played a fundamental role in triggering ice growth. Here we revisit the middle Miocene Southern Ocean temperature evolution using clumped isotope and lipid biomarker temperature proxies. Our records indicate that the Southern Ocean cooling and the associated salinity decrease occurred in phase with the expansion of the Antarctic ice sheet. We demonstrate that the timing and magnitude of the Southern Ocean temperature change seen in previous reconstructions can be explained if we consider pH as an additional, non-thermal, control on foraminiferal Mg/Ca ratios. Therefore, our new dataset challenges the view of a thermal isolation of Antarctica preceding ice sheet expansion, and suggests a strong coupling between Southern Ocean conditions and Antarctic ice volume in times of declining atmospheric carbon dioxide. © 2020, The Author(s), under exclusive licence to Springer Nature Limited.
英文关键词	atmosphere-ocean coupling; biomarker; climate variation; cooling; expansion; Miocene; planktonic foraminifera; proxy climate record; reconstruction; sea surface temperature; temperature effect; Antarctic Ice Sheet; Antarctica; Southern Ocean
语种	英语
来源期刊	Nature Geoscience
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/206804
作者单位	Bjerknes Centre for Climate Research and Department of Earth Science, University of Bergen, Bergen, Norway; Max Planck Institute for Chemistry, Mainz, Germany; Geological Institute, ETH Zurich, Zurich, Switzerland; Max Planck Institute for Chemistry, Mainz, Germany
推荐引用方式 GB/T 7714	Leutert T.J.,Auderset A.,Martínez-García A.,et al. Coupled Southern Ocean cooling and Antarctic ice sheet expansion during the middle Miocene[J],2020,13(9).
APA	Leutert T.J.,Auderset A.,Martínez-García A.,Modestou S.,&Meckler A.N..(2020).Coupled Southern Ocean cooling and Antarctic ice sheet expansion during the middle Miocene.Nature Geoscience,13(9).
MLA	Leutert T.J.,et al."Coupled Southern Ocean cooling and Antarctic ice sheet expansion during the middle Miocene".Nature Geoscience 13.9(2020).