Sea-ice response to climate change in the Bering Sea during the Mid-Pleistocene Transition

QUATERNARY SCIENCE REVIEWS

卷:259

Article

Worne, Savannah^1,2  Stroynowski, Zuzia³  Kender, Sev^1,4  Swann, George E. A.² 

[1] British Geol Survey, Nottingham NG12 5GG, England

[2] Univ Nottingham, Sch Geog, Ctr Environm Geochem, Nottingham NG7 2RD, England

[3] Inst Portugues Mar & Atmosfera IPMA, Av Doutor Alfredo Magalhaes Ramalho 6, P-1495165 Lisbon, Portugal

[4] Univ Exeter, Camborne Sch Mines, Penryn Campus, Penryn TR10 9FE, Cornwall, England

关键词: Sea-ice;    Bering Sea;    Mid-Pleistocene Transition;    Diatoms;    IODP Site U1343;   

DOI  :  10.1016/j.quascirev.2021.106918

来源: Elsevier

【 摘 要 】

Sea-ice is believed to be an important control on climatic changes through the Mid-Pleistocene Transition (MPT; 0.6-1.2 Ma). However, the low resolution/short timescale of existing reconstructions prevents a full evaluation of these dynamics. Here, diatom assemblages from the Bering Sea are used to investigate sea-ice evolution on millennial timescales. We find that sea-ice was primarily controlled by ice-sheet/sea level fluctuations that modulated warm water flow into the Bering Sea. Facilitated by an amplified Walker circulation, sea-ice expansion began at similar to 1.05 Ma with a step-increase during the 900 kyr event. Maximal pack ice was simultaneous with glacial maxima, suggesting sea-ice was responding to, rather than modulating ice-sheet dynamics, as proposed by the sea-ice switch hypothesis. Significant pack ice, coupled with Bering Strait closure at 0.9 Ma, indicates that brine rejection played an integral role in the glacial expansion/deglacial collapse of intermediate waters during the MPT, regulating subarctic ocean-atmospheric exchanges of CO2. Crown Copyright (C) 2021 Published by Elsevier Ltd.

【 授权许可】

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