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

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Worne, S. ORCID: 0000-0001-7967-0864, Stroynowski, Z., Kender, S. and Swann, G.E.A., 2021. Sea-ice response to climate change in the Bering Sea during the Mid-Pleistocene Transition. Quaternary Science Reviews, 259: 106918. ISSN 0277-3791

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Official URL: https://doi.org/10.1016/j.quascirev.2021.106918

Abstract

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 ∼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.

Item Type:

Journal article

Publication Title:

Quaternary Science Reviews

Creators:

Worne, S., Stroynowski, Z., Kender, S. and Swann, G.E.A.

Publisher:

Elsevier BV

Date:

1 May 2021

Volume:

259