Lynch-Stieglitz, Jean and Schmidt, Matthew W. and Gene Henry, L. and Curry, William B. and Skinner, Luke C. and Mulitza, Stefan and Zhang, Rong and Chang, Ping (2014) Muted change in Atlantic overturning circulation over some glacial-aged Heinrich events. Nature Geoscience, 7 (2). pp. 144-150. ISSN 1752-0894 EISSN:1752-0908 DOI https://doi.org/10.1038/ngeo2045
![]() |
Text
ngeo2045.pdf - Published Version Restricted to Registered users only Download (1MB) |
|
|
Text
ngeo2045-s1.pdf - Supplemental Material Download (2MB) | Preview |
|
![]() |
Text
ngeo2045-s2.xls - Supplemental Material Download (132kB) |
|
![]()
|
Image
ngeo2045-f1.jpg - Published Version Download (96kB) | Preview |
Abstract
Heinrich events—surges of icebergs into the North Atlantic Ocean—punctuated the last glacial period. The events are associated with millennial-scale cooling in the Northern Hemisphere. Fresh water from the melting icebergs is thought to have interrupted the Atlantic meridional overturning circulation, thus minimizing heat transport into the northern North Atlantic. The northward flow of warm water passes through the Florida Straits and is reflected in the distribution of seawater properties in this region. Here we investigate the northward flow through this region over the past 40,000 years using oxygen isotope measurements of benthic foraminifera from two cores on either side of the Florida Straits. These measurements allow us to estimate water density, which is related to flow through the thermal wind balance. We infer a substantial reduction of flow during Heinrich Event 1 and the Younger Dryas cooling, but little change during Heinrich Events 2 and 3, which occurred during an especially cold phase of the last glacial period. We speculate that because glacial circulation was already weakened before the onset of Heinrich Events 2 and 3, freshwater forcing had little additional effect. However, low-latitude climate perturbations were observed during all events. We therefore suggest that these perturbations may not have been directly caused by changes in heat transport associated with Atlantic overturning circulation as commonly assumed.
Item Type: | Article |
---|---|
Uncontrolled Keywords: | 2013AREP, IA67, |
Subjects: | 01 - Climate Change and Earth-Ocean Atmosphere Systems |
Divisions: | 01 - Climate Change and Earth-Ocean Atmosphere Systems |
Journal or Publication Title: | Nature Geoscience |
Volume: | 7 |
Page Range: | pp. 144-150 |
Identification Number: | https://doi.org/10.1038/ngeo2045 |
Depositing User: | Sarah Humbert |
Date Deposited: | 27 Feb 2014 23:51 |
Last Modified: | 05 Mar 2014 17:19 |
URI: | http://eprints.esc.cam.ac.uk/id/eprint/2973 |
Actions (login required)
![]() |
View Item |