Turney et al 2015 - Geophy Res Lett.pdf (2.41 MB)
Obliquity-driven expansion of North Atlantic sea ice during the last glacial
journal contribution
posted on 2023-05-18, 17:39 authored by Turney, CSM, Thomas, ZA, Hutchinson, DK, Bradshaw, CJA, Barry BrookBarry Brook, England, MH, Fogwill, CJ, Jones, RT, Palmer, J, Hughen, KA, Cooper, ANorth Atlantic late Pleistocene climate (60,000 to 11,650 years ago) was characterized by abrupt and extreme millennial duration oscillations known as Dansgaard-Oeschger (D-O) events. However, during the Last Glacial Maximum (LGM) 23,000 to 19,000 cal years ago (23 to 19 ka), no D-O events are observed in the Greenland ice cores. Our new analysis of the Greenland δ18O record reveals a switch in the stability of the climate system around 30 ka, suggesting that a critical threshold was passed. Climate system modeling suggests that low axial obliquity at this time caused vastly expanded sea ice in the Labrador Sea, shifting Northern Hemisphere westerly winds south and reducing the strength of meridional overturning circulation. The results suggest that these feedbacks tipped the climate system into full glacial conditions, leading to maximum continental ice growth during the LGM.
History
Publication title
Geophysical Research LettersVolume
42Issue
23Pagination
10382-10390ISSN
0094-8276Department/School
School of Natural SciencesPublisher
Amer Geophysical UnionPlace of publication
2000 Florida Ave Nw, Washington, USA, Dc, 20009Rights statement
Copyright 2015 American Geophysical UnionRepository Status
- Open