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The Younger Dryas cold interval as viewed from central Greenland

Greenland Temperature Plot after Alley 2000 The Younger Dryas cold interval as viewed from central Greenland
Quaternary Science Reviews
Volume 19, Issues 1-5, 1 January 2000, Pages 213-226.

Richard B. Alley
Department of Geosciences and Environment Institute, The Pennsylvania State University, Deike Building, University Park, PA 16802, USA

Greenland ice-core records provide an exceptionally clear picture of many aspects of abrupt climate changes, and particularly of those associated with the Younger Dryas event, as reviewed here. Well-preserved annual layers can be counted confidently, with only ~1% errors for the age of the end of the Younger Dryas ~11,500 years before present. Ice-flow corrections allow reconstruction of snow accumulation rates over tens of thousands of years with little additional uncertainty. Glaciochemical and particulate data record atmospheric-loading changes with little uncertainty introduced by changes in snow accumulation. Confident paleothermometry is provided by site-specific calibrations using ice-isotopic ratios, borehole temperatures, and gas-isotopic ratios. Near-simultaneous changes in ice-core paleoclimatic indicators of local, regional, and more-widespread climate conditions demonstrate that much of the Earth experienced abrupt climate changes synchronous with Greenland within thirty years or less. Post-Younger Dryas changes have not duplicated the size, extent and rapidity of these paleoclimatic changes.
To read or view the full study, please visit the Science Direct website.

Download the Data from the WDC Paleo Archive.

This figure, adapted from the NRC (2002) report Abrupt Climate Change: Inevitable Surprises, comes from data in Alley (2000) and Cuffey and Clow (1997). It shows the clear, abrupt increases in temperature in the Greenland Ice Sheet Project 2 (GISP2) record at the end of the last glacial period and at the end of the Younger Dryas. The cooling as temperatures returned to the glacial conditions of the Younger Dryas takes place over a longer period in a step-wise fashion.

References cited:
Alley, R.B. 2000. The Younger Dryas cold interval as viewed from central Greenland. Quaternary Science Reviews 19: 213-226.

Cuffey, K.M., and G.D. Clow. 1997. Temperature, accumulation, and ice sheet elevation in central Greenland through the last deglacial transition. Journal of Geophysical Research 102:26383-26396.

National Research Council. 2002. Abrupt Climate Change: Inevitable Surprises, US National Academy of Sciences, National Research Council Committee on Abrupt Climate Change, National Academy Press, 2002, Washington, D.C. 230 p.

The Greenland Ice Sheet Project Two (GISP2) core data is also available on the WDC Paleo website.

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10 May 2004