Abstract
Collapse of ice sheets can cause significant sea level rise and widespread climate change. We examine the climatic response to meltwater generated by the collapse of the Cordilleran-Laurentide ice saddle (North America) ~14.5 thousand years ago (ka) using a high-resolution drainage model coupled to an ocean-atmosphere-vegetation general circulation model. Equivalent to 7.26 m global mean sea level rise in 340 years, the meltwater caused a 6 sverdrup weakening of Atlantic Meridional Overturning Circulation (AMOC) and widespread Northern Hemisphere cooling of 1–5°C. The greatest cooling is in the Atlantic sector high latitudes during Boreal winter (by 5–10°C), but there is also strong summer warming of 1–3°C over eastern North America. Following recent suggestions that the saddle collapse was triggered by the Bølling warming event at ~14.7–14.5 ka, we conclude that this robust submillennial mechanism may have initiated the end of the warming and/or the Older Dryas cooling through a forced AMOC weakening.
Original language | English (US) |
---|---|
Pages (from-to) | 383-392 |
Number of pages | 10 |
Journal | Geophysical Research Letters |
Volume | 44 |
Issue number | 1 |
DOIs | |
State | Published - Jan 16 2017 |
Bibliographical note
Publisher Copyright:©2016. The Authors.
Keywords
- AMOC
- Older Dryas
- ice sheet melt
- saddle collapse