Letter abstract
Nature Geoscience 1, 520-523 (2008)
Published online: 1 August 2008 | doi:10.1038/ngeo263
An abrupt wind shift in western Europe at the onset of the Younger Dryas cold period
Achim Brauer1, Gerald H. Haug2,3, Peter Dulski1, Daniel M. Sigman4 & Jörg F. W. Negendank1
The Younger Dryas cooling 12,700 years ago is one of the most abrupt climate changes observed in Northern Hemisphere palaeoclimate records1, 2, 3, 4. Annually laminated lake sediments are ideally suited to record the dynamics of such abrupt changes, as the seasonal deposition responds immediately to climate, and the varve counts provide an accurate estimate of the timing of the change. Here, we present sub-annual records of varve microfacies and geochemistry from Lake Meerfelder Maar in western Germany, providing one of the best dated records of this climate transition5. Our data indicate an abrupt increase in storminess during the autumn to spring seasons, occurring from one year to the next at 12,679 yr BP, broadly coincident with other changes in this region. We suggest that this shift in wind strength represents an abrupt change in the North Atlantic westerlies towards a stronger and more zonal jet. Changes in meridional overturning circulation alone cannot fully explain the changes in European climate6, 7; we suggest the observed wind shift provides the mechanism for the strong temporal link between North Atlantic Ocean overturning circulation and European climate during deglaciation.
- GFZ German Research Centre for Geosciences, Telegrafenberg, D-14473 Potsdam, Germany
- Geological Institute, Department of Earth Sciences, ETH Zürich, 8092 Zürich, Switzerland
- DFG-Leibniz Center for Surface Process and Climate Studies, Institute for Geosciences, Potsdam University, 14476 Potsdam, Germany
- Department of Geosciences, Princeton University, Princeton, New Jersey 08544, USA
Correspondence to: Achim Brauer1 e-mail: brau@gfz-potsdam.de
No comments:
Post a Comment