TY - JOUR
T1 - Obliquity-driven expansion of North Atlantic sea ice during the last glacial
AU - Turney, Chris
AU - Thomas, Zoe
AU - Hutchinson, David
AU - Bradshaw, Corey
AU - Brook, Barry
AU - England, Matthew
AU - Fogwill, Christopher
AU - Jones, Richard
AU - Palmer, Jonathan
AU - Hughen, Konrad
AU - Cooper, Alan
PY - 2015/12/16
Y1 - 2015/12/16
N2 -
North 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 δ
18
O 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.
AB -
North 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 δ
18
O 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.
KW - abrupt climate change
KW - geochronology
KW - Greenland ice cores
KW - late Pleistocene
KW - meridional overturning circulation
KW - tipping point
UR - http://www.scopus.com/inward/record.url?scp=84953639500&partnerID=8YFLogxK
U2 - 10.1002/2015GL066344
DO - 10.1002/2015GL066344
M3 - Article
SN - 0094-8276
VL - 42
SP - 10382
EP - 10390
JO - Geophysical Research Letters
JF - Geophysical Research Letters
IS - 23
ER -