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Northward Shifts in the Polar Front Preceded Bølling and Holocene Warming in Southwestern Scandinavia
Author(s) -
Cowling O. C.,
Thomas E. K.,
Svendsen J. I.,
Mangerud J.,
Vasskog K.,
Haflidason H.
Publication year - 2020
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2020gl088153
Subject(s) - geology , deglaciation , oceanography , polar front , north atlantic deep water , abrupt climate change , younger dryas , holocene , front (military) , climatology , climate change , stadial , global warming , thermohaline circulation , effects of global warming
The last deglaciation in northern Europe provides an opportunity to study the hydrologic component of abrupt climate shifts in a region with complex interactions between ice sheets and oceanic and atmospheric circulation. We use leaf wax hydrogen isotopes (δ 2 H) to reconstruct summer precipitation δ 2 H and aridity in southwestern Norway from 15.8 to 11.5 ka. We identify transitions to a more proximal moisture source before the ends of Heinrich Stadial 1 and the Younger Dryas, prior to local warming and increased primary productivity in both instances. We infer these changes in moisture delivery to southwestern Norway to be a response to northward shifts in the polar front caused by warm water intrusion into the North Atlantic, which preceded abrupt warming in the circum‐North Atlantic. These results suggest that moisture transport pathways shift northward as warm surface ocean water reaches higher latitudes in the North Atlantic.