Understanding climate
for the benefit of society

Causes of abrupt climate change

What caused abrupt climate swings known as the Dansgaard-Oeschger events of the last ice age?

Dansgaard-Oeschger
The Northern Seas. Purple arrows represent surface currents, dashed orange arrows deep currents, and SPG the subpolar gyre. Shading shows annual mean sea surface temperature and sea ice concentration. From Li & Born, 2019.

Written by Camille Li from the Bjerknes Centre and the Geophysical Institute at the University of Bergen.

In this review, we speculate that the subpolar North Atlantic hit a sweet spot, possible in a glacial world but not today, where positive feedbacks between winds, sea ice and ocean circulation created large, sustained climate oscillations.

Reference

Camille Li, Andreas Born: Coupled atmosphere-ice-ocean dynamics in Dansgaard-Oeschger events,Quaternary Science Reviews, Volume 203, 2019,Pages 1-20,ISSN 0277-3791, doi.org/10.1016/j.quascirev.2018.10.031.