Gregoire, LJ, Valdes, PJ and Payne, AJ (2015) The relative contribution of orbital forcing and greenhouse gases to the North American deglaciation. Geophysical Research Letters, 42 (22). pp. 9970-9979. ISSN 0094-8276
Abstract
Understanding what drove Northern Hemisphere ice sheet melt during the last deglaciation (21–7 ka) can help constrain how sensitive contemporary ice sheets are to greenhouse gas (GHGs) changes. The roles of orbital forcing and GHGs in the deglaciation have previously been modelled, but not yet quantified. Here, for the first time we calculate the relative effect of these forcings on the North American deglaciation by driving a dynamical ice sheet model (GLIMMER-CISM) with a set of un-accelerated transient deglacial simulations with a full primitive equation based ocean atmosphere general circulation model (FAMOUS). We find that by 9 ka, orbital forcing has caused 50% of the deglaciation, GHG 30% and the interaction between the two 20%. Orbital forcing starts affecting the ice volume at 19 ka, 2,000 years before CO2 starts increasing in our experiments, a delay which partly controls their relative effect.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2015, American Geophysical Union. All Rights Reserved. Reproduced in accordance with the publisher's self-archiving policy. |
Keywords: | deglaciation; ice sheets; North America; orbit; greenhouse gases; Milankovic |
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst for Climate & Atmos Science (ICAS) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 20 Nov 2015 12:10 |
Last Modified: | 23 May 2016 01:35 |
Published Version: | http://dx.doi.org/10.1002/2015GL066005 |
Status: | Published |
Publisher: | American Geophysical Union (AGU) |
Identification Number: | 10.1002/2015GL066005 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:92096 |