A model-data comparison of δ13C in the glacial Atlantic Ocean
Article first published online: 10 SEP 2011
Copyright 2011 by the American Geophysical Union.
Volume 26, Issue 3, September 2011
How to Cite
2011), A model-data comparison of δ13C in the glacial Atlantic Ocean, Paleoceanography, 26, PA3220, doi:10.1029/2010PA002085., , , and (
- Issue published online: 10 SEP 2011
- Article first published online: 10 SEP 2011
- Manuscript Accepted: 13 JUN 2011
- Manuscript Revised: 31 MAY 2011
- Manuscript Received: 24 NOV 2010
- Last Glacial Maximum;
- benthic foraminifera;
- carbon isotopes;
- meridional overturning circulation
 We compare a compilation of 220 sediment core δ13C data from the glacial Atlantic Ocean with three-dimensional ocean circulation simulations including a marine carbon cycle model. The carbon cycle model employs circulation fields which were derived from previous climate simulations. All sediment data have been thoroughly quality controlled, focusing on epibenthic foraminiferal species (such as Cibicidoides wuellerstorfi or Planulina ariminensis) to improve the comparability of model and sediment core carbon isotopes. The model captures the general δ13C pattern indicated by present-day water column data and Late Holocene sediment cores but underestimates intermediate and deep water values in the South Atlantic. The best agreement with glacial reconstructions is obtained for a model scenario with an altered freshwater balance in the Southern Ocean that mimics enhanced northward sea ice export and melting away from the zone of sea ice production. This results in a shoaled and weakened North Atlantic Deep Water flow and intensified Antarctic Bottom Water export, hence confirming previous reconstructions from paleoproxy records. Moreover, the modeled abyssal ocean is very cold and very saline, which is in line with other proxy data evidence.