Younger Dryas deglaciation of Scotland driven by warming summers

The Younger Dryas Stadial (YDS; similar to 12,900-11,600 y ago) in the Northern Hemisphere is classically defined by abrupt cooling and renewed glaciation during the last glacial- interglacial transition. Although this event involved a global reorganization of atmospheric and oceanic circulation [De...

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Bibliographic Details
Main Authors: Bromley, Gordon R. M., Putnam, Aaron E., Rademaker, Kurt M., Lowell, Thomas V., Schaefer, Joerg M., Hall, Brenda, Winckler, Gisela, Birkel, Sean D., Borns, Harold W.
Format: Article in Journal/Newspaper
Language:English
Published: National Academy of Sciences 2018
Subjects:
ABRUPT CLIMATE-CHANGE
EAST GREENLAND IMPLICATIONS
RADIOCARBON-DATES
WESTERN NORWAY
PALEOCLIMATIC IMPLICATIONS
ENVIRONMENTAL HISTORY
GLACIER RESPONSE
POLLEN DIAGRAMS
CIRQUE GLACIERS
HEINRICH EVENTS
Greenland
Norway
East Greenland
glacier
Ice cap
North Atlantic
Online Access:http://hdl.handle.net/10379/14777
https://doi.org/10.13025/19901
https://doi.org/10.1073/pnas.1321122111
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Summary:The Younger Dryas Stadial (YDS; similar to 12,900-11,600 y ago) in the Northern Hemisphere is classically defined by abrupt cooling and renewed glaciation during the last glacial- interglacial transition. Although this event involved a global reorganization of atmospheric and oceanic circulation [Denton GH, Alley RB, Comer GC, Broecker WS (2005) Quat Sci Rev 24: 1159-1182], the magnitude, seasonality, and geographical footprint of YDS cooling remain unresolved and pose a challenge to our understanding of abrupt climate change. Here, we present a deglacial chronology from Scotland, immediately downwind of the North Atlantic Ocean, indicating that the Scottish ice cap disintegrated during the first half of the YDS. We suggest that stratification of the North Atlantic Ocean resulted in amplified seasonality that, paradoxically, stimulated a severe wintertime climate while promoting warming summers through solar heating of the mixed layer. This latter process drove deglaciation of downwind landmasses to completion well before the end of the YDS. This research is supported by grants from the Dan and Betty Churchill Exploration Fund and the Lamont–Doherty Earth Observatory (LDEO) Climate Center. G.R.M.B. was supported by a LDEO postdoctoral fellowship. A.E.P. was supported by the Gary Comer Science and Education Foundation, the National Oceanographic and Atmospheric Administration, and a LDEO postdoctoral fellowship. This is LDEO contribution no. 7772. peer-reviewed

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