Estimated strength of the Atlantic overturning circulation during the last deglaciation

Ritz, Stefan; Stocker, Thomas; Grimalt, J. O.; Menviel, Laurie; Timmermann, A. (2013). Estimated strength of the Atlantic overturning circulation during the last deglaciation. Nature geoscience, 6(3), pp. 208-212. Nature Publishing Group 10.1038/ngeo1723

Text ngeo1723.pdf - Published Version Restricted to registered users only Available under License Publisher holds Copyright. Download (853kB)

The Atlantic meridional overturning circulation affects the latitudinal distribution of heat, and is a key component of the climate system. Proxy reconstructions, based on sedimentary Pa-231/Th-230 ratios and the difference between surface-and deep-water radiocarbon ages, indicate that during the last glacial period, the overturning circulation was reduced during millennial-scale periods of cooling(1-5). However, much debate exists over the robustness of these proxies(6-8). Here e combine proxy reconstructions of sea surface and air temperatures and a global climate model to quantitatively estimate changes in the strength of the Atlantic meridional overturning circulation during the last glacial period. We find that, relative to the Last Glacial Maximum, the overturning circulation was reduced by approximately 14 Sv during the cold Heinrich event 1. During the Younger Dryas cold event, the overturning circulation was reduced by approximately 12 Sv, relative to the preceding warm interval. These changes are consistent with qualitative estimates of the overturning circulation from sedimentary Pa-231/Th-230 ratios. In addition, we find that the strength of the overturning circulation during the Last Glacial Maximum and the Holocene epoch are indistinguishable within the uncertainty of the reconstruction.

Interest & Impact

Downloads

1 since deposited on 29 Sep 2014
0 in the past 12 months

Citations

5 Citations in Web of Science ®
6 Citations in Scopus

Search

in Google Scholar™

Services

Actions (login required)

Edit item

Actions (login required)

Edit item