Medieval Irish chronicles reveal persistent volcanic forcing of severe winter cold events, 431 - 1649 CE

• Published in: Environmental Research Letters
• Main Authors: Hennessy, Mark, Ludlow, Francis
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2013
• Subjects: volcano-climate; palaeoclimate; temperature extremes; Ireland; Northeast Atlantic; ice-cores; medieval chronicles; Making Ireland; Smart & Sustainable Planet; Agriculture; settlement and society in medieval Ireland; Annals; CLIMATE; CLIMATE CHANGE; CLIMATE-CHANGE; Chronicles; Climate Change Impacts on the Environment; Climate History; Early Medieval History; GLOBAL CLIMATE-CHANGE; HOLOCENE CLIMATE; Irish History; Late Medieval Ireland; 1166-1534; MEDIEVAL; Medieval History; Medieval Ireland; Medieval Sources; Medieval Studies; PALEOCLIMATE; VOLCANIC ACTIVITY; Volcanic Aerosol; Volcanic Eruptions; climate change impacts; climate research; volcanic dust veil; Dwyer; Greenland; Hennessy; Leahy; McCarthy; Smyth; Greenland Ice Sheet Project; ice core; Ice Sheet
• Online Access: http://hdl.handle.net/2262/66682; http://people.tcd.ie/mhnnessy; http://people.tcd.ie/fludlow; https://doi.org/10.1088/1748-9326/8/2/024035; http://iopscience.iop.org/article/10.1088/1748-9326/8/2/024035

PUBLISHED Mark Hennessy (Joint Author) Explosive volcanism resulting in stratospheric injection of sulfate aerosol is a major driver of regional to global climatic variability on interannual and longer timescales. However, much of our knowledge of the climatic impact of volcanism derives from the limited number of eruptions that have occurred in the modern period during which meteorological instrumental records are available. We present a uniquely long historical record of severe short-term cold events from Irish chronicles, 431?1649 CE, and test the association between cold event occurrence and explosive volcanism. Thirty eight (79%) of 48 volcanic events identified in the sulfate deposition record of the Greenland Ice Sheet Project 2 ice-core correspond to 37 (54%) of 69 cold events in this 1219 year period. We show this association to be statistically significant at the 99.7% confidence level, revealing both the consistency of response to explosive volcanism for Ireland?s climatically sensitive Northeast Atlantic location and the large proportional contribution of volcanism to historic cold event frequencies here. Our results expose, moreover, the extent to which volcanism has impacted winter-season climate for the region, and can help to further resolve the complex spatial patterns of Northern Hemisphere winter-season cooling versus warming after major eruptions. Explosive volcanism resulting in stratospheric injection of sulfate aerosol is a major driver of regional to global climatic variability on interannual and longer timescales. However, much of our knowledge of the climatic impact of volcanism derives from the limited number of eruptions that have occurred in the modern period during which meteorological instrumental records are available. We present a uniquely long historical record of severe short-term cold events from Irish chronicles, 431?1649 CE, and test the association between cold event occurrence and explosive volcanism. Thirty eight (79%) of 48 volcanic events identified in the sulfate deposition record of the Greenland Ice Sheet Project 2 ice-core correspond to 37 (54%) of 69 cold events in this 1219 year period. We show this association to be statistically significant at the 99.7% confidence level, revealing both the consistency of response to explosive volcanism for Ireland?s climatically sensitive Northeast Atlantic location and the large proportional contribution of volcanism to historic cold event frequencies here. Our results expose, moreover, the extent to which volcanism has impacted winter-season climate for the region, and can help to further resolve the complex spatial patterns of Northern Hemisphere winter-season cooling versus warming after major eruptions We thank Brian ? an Nolan, William Nolan, Michael Mc- Cormick, Bruce Campbell, Arlene Crampsie, Valerie Hall, Andrei Kurbatov, Michael Monk, Daniel McCarthy, Peter Coxon, William J Smyth, Stephen McCarron, David Brown, David Dickson, Poul Holm, Barry O?Dwyer, Michael Sigl, Kees Nooren, Edward R Cook, Gill Plunkett, Chaochao Gao and Alan Robock for discussion of the results and/or the manuscript. Francis Ludlow was funded to undertake part of this work by a Ziff Environmental Fellowship from the Harvard University Center for the Environment, a Government of Ireland Postgraduate Scholarship from the Irish Research Council for the Humanities and Social Sciences, and additional funding from the Irish Environmental Protection Agency?s Climate Change Research Programme (2007/CCRP/2.7?Extreme Weather, Climatic Shifts & Nat- ural Disasters in Ireland). Alexander R Stine was funded to undertake part of this research by a Kernan Brothers Environmental Fellowship from the Harvard University Center for the Environment, and by a National Science Foundation grant (NSF ATM-0902374). Francis Ludlow and Alexander R Stine thank the Harvard Open-Access Publishing Equity (HOPE) Fund for contributing to the open-access article charge. Paul Leahy and Gerard Kiely were funded by the Irish Environmental Protection Agency?s Climate Change Research Programme (2007/CCRP/2.7). Paul Leahy and Paul A Mayewski thank the Science Foundation Ireland and the Climate Change Institute, University of Maine, respectively, for their contribution to the article charge. We thank the Corpus of Electronic Texts project (ucc.ie/celt) for access to hypertext editions of sources and word counts of the Irish Annals. We thank the two anonymous reviewers for their valuable comments on the manuscript.