Muted change in Atlantic overturning circulation over some glacial-aged Heinrich events
Schmidt, Matthew W.
Henry, L. Gene
Curry, William B.
Skinner, Luke C.
MetadataShow full item record
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. Freshwater 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, which allow us to estimate water density, which is related to flow via the thermal wind relation. We infer a substantial reduction of flow during Heinrich Event 1 and the Heinrich-like 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 these perturbations may not have been directly caused by changes in heat transport associated with Atlantic overturning circulation as commonly assumed.
Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in Nature Geoscience 7 (2014):144–150, doi:10.1038/ngeo2045.
Suggested CitationPreprint: Lynch-Stieglitz, Jean, Schmidt, Matthew W., Henry, L. Gene, Curry, William B., Skinner, Luke C., Mulitza, Stefan, Zhang, Rong, Chang, Ping, "Muted change in Atlantic overturning circulation over some glacial-aged Heinrich events", 2013-11-11, https://doi.org/10.1038/ngeo2045, https://hdl.handle.net/1912/6513
Showing items related by title, author, creator and subject.
Mass-induced sea level change in the northwestern North Pacific and its contribution to total sea level change Cheng, Xuhua; Li, Lijuan; Du, Yan; Wang, Jing; Huang, Rui Xin (John Wiley & Sons, 2013-08-02)Over the period 2003–2011, the Gravity Recovery and Climate Experiment (GRACE) satellite pair revealed a remarkable variability in mass-induced sea surface height (MSSH) in the northwestern North Pacific. A significant ...
Pendleton, Elizabeth A.; Thieler, E. Robert; Williams, S. Jeffress (Coastal Education and Research Foundation, 2010-01)In 2001, the U.S. Geological Survey began conducting scientific assessments of coastal vulnerability to potential future sea- and lake-level changes in 22 National Park Service sea- and lakeshore units. Coastal park units ...
Abrupt climate change as an important agent of ecological change in the Northeast U.S. throughout the past 15,000 years Shuman, Bryan N.; Newby, Paige E.; Donnelly, Jeffrey P. (2009-03-30)We use a series of tests to evaluate two competing hypotheses about the association of climate and vegetation trends in the northeastern United States over the past 15 kyrs. First, that abrupt climate changes on the scale ...