Was millennial scale climate change during the Last Glacial triggered by explosive volcanism?

Baldini, J.U.L.; Brown, R.J.; McElwaine, J.N.

Abstract

The mechanisms responsible for millennial scale climate change within glacial time intervals are equivocal. Here we show that all eight known radiometrically-dated Tambora-sized or larger NH eruptions over the interval 30 to 80 ka BP are associated with abrupt Greenland cooling (>95% confidence). Additionally, previous research reported a strong statistical correlation between the timing of Southern Hemisphere volcanism and Dansgaard-Oeschger (DO) events (>99% confidence), but did not identify a causative mechanism. Volcanic aerosol-induced asymmetrical hemispheric cooling over the last few hundred years restructured atmospheric circulation in a similar fashion as that associated with Last Glacial millennial-scale shifts (albeit on a smaller scale). We hypothesise that following both recent and Last Glacial NH eruptions, volcanogenic sulphate injections into the stratosphere cooled the NH preferentially, inducing a hemispheric temperature asymmetry that shifted atmospheric circulation cells southward. This resulted in Greenland cooling, Antarctic warming, and a southward shifted ITCZ. However, during the Last Glacial, the initial eruption-induced climate response was prolonged by NH glacier and sea ice expansion, increased NH albedo, AMOC weakening, more NH cooling, and a consequent positive feedback. Conversely, preferential SH cooling following large SH eruptions shifted atmospheric circulation to the north, resulting in the characteristic features of DO events.

Citation

Baldini, J., Brown, R., & McElwaine, J. (2015). Was millennial scale climate change during the Last Glacial triggered by explosive volcanism?. Scientific Reports, 5, Article 17442. https://doi.org/10.1038/srep17442

• Journal Article Type: Article
• Acceptance Date: Oct 29, 2015
• Online Publication Date: Nov 30, 2015
• Publication Date: Nov 30, 2015
• Deposit Date: Nov 30, 2015
• Publicly Available Date: Oct 20, 2016
• Journal: Scientific Reports
• Electronic ISSN: 2045-2322
• Publisher: Nature Research
• Peer Reviewed: Peer Reviewed
• Volume: 5
• Article Number: 17442
• DOI: https://doi.org/10.1038/srep17442
• Public URL: https://durham-repository.worktribe.com/output/1417593