气候变化领域集成服务门户(CCPortal): Causes of ice age intensification across the mid-pleistocene transition

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DOI	10.1073/pnas.1702143114
	Causes of ice age intensification across the mid-pleistocene transition
	Chalk T.B.; Hain M.P.; Foster G.L.; Rohling E.J.; Sexton P.F.; Badger M.P.S.; Cherry S.G.; Hasenfratz A.P.; Haug G.H.; Jaccard S.L.; Martínez-García A.; Pälike H.; Pancost R.D.; Wilson P.A.
发表日期	2017
ISSN	0027-8424
起始页码	13114
结束页码	13119
卷号	114 期号:50
英文摘要	During the Mid-Pleistocene Transition (MPT; 1,200–800 kya), Earth’s orbitally paced ice age cycles intensified, lengthened from ~40,000 (~40 ky) to ~100 ky, and became distinctly asymmetrical. Testing hypotheses that implicate changing atmospheric CO2 levels as a driver of the MPT has proven difficult with available observations. Here, we use orbitally resolved, boron isotope CO2 data to show that the glacial to interglacial CO2 difference increased from ~43 to ~75 μatm across the MPT, mainly because of lower glacial CO2 levels. Through carbon cycle modeling, we attribute this decline primarily to the initiation of substantive dust-borne iron fertilization of the Southern Ocean during peak glacial stages. We also observe a twofold steepening of the relationship between sea level and CO2-related climate forcing that is suggestive of a change in the dynamics that govern ice sheet stability, such as that expected from the removal of subglacial regolith or interhemispheric ice sheet phase-locking. We argue that neither ice sheet dynamics nor CO2 change in isolation can explain the MPT. Instead, we infer that the MPT was initiated by a change in ice sheet dynamics and that longer and deeper post-MPT ice ages were sustained by carbon cycle feedbacks related to dust fertilization of the Southern Ocean as a consequence of larger ice sheets.
英文关键词	Boron isotopes; Carbon dioxide; Geochemistry; MPT; Paleoclimate
语种	英语
scopus关键词	boron; carbon dioxide; isotope; oxygen 18; Article; atmosphere; climate change; environmental temperature; geochemistry; greenhouse gas; ice age; Mid Pleistocene Transition; paleoclimate; Pleistocene; priority journal
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/160568
作者单位	Chalk, T.B., Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Southampton, SO14 3ZH, United Kingdom, Department of Physical Oceanography, Woods Hole Oceanographic Institution, Woods HoleMA 02543, United States; Hain, M.P., Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Southampton, SO14 3ZH, United Kingdom; Foster, G.L., Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Southampton, SO14 3ZH, United Kingdom; Rohling, E.J., Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Southampton, SO14 3ZH, United Kingdom, Research School of Earth Sciences, Australian National University, Canberra, 2601, Australia; Sexton, P.F., School of Environment, Earth and Ecosystem Sciences, Open University, Milton Keynes, MK7 6AA, United Kingdom; Badger, M.P.S., School of Environment, Earth and Ecosystem Sciences, Open University, Milton Keynes, MK7 ...
推荐引用方式 GB/T 7714	Chalk T.B.,Hain M.P.,Foster G.L.,et al. Causes of ice age intensification across the mid-pleistocene transition[J],2017,114(50).
APA	Chalk T.B..,Hain M.P..,Foster G.L..,Rohling E.J..,Sexton P.F..,...&Wilson P.A..(2017).Causes of ice age intensification across the mid-pleistocene transition.Proceedings of the National Academy of Sciences of the United States of America,114(50).
MLA	Chalk T.B.,et al."Causes of ice age intensification across the mid-pleistocene transition".Proceedings of the National Academy of Sciences of the United States of America 114.50(2017).