image: South Sawtooth Lake on Ellesmere Island, Canada. view more
Credit: Image credit: Pierre Francus
Researchers report a reconstruction of variations in North Atlantic surface temperatures over the past 2,900 years. Sea surface temperatures in the North Atlantic have undergone large-scale oscillations, known as the Atlantic Multidecadal Variability (AMV), during the approximately 160-year instrumental record. This variability has climatic connections to regions far beyond the North Atlantic, but its behavior over periods longer than the instrumental record is poorly understood. Francois Lapointe and colleagues observed a significant negative correlation between the instrumental AMV and titanium (Ti) levels in an annually laminated lake sediment core from South Sawtooth Lake (SSL), Ellesmere Island, Canada. Levels of Ti were also negatively correlated with Arctic air pressure and North Atlantic sea surface temperature anomalies, which are themselves correlated with AMV, suggesting that the sediment Ti record is a reliable proxy for AMV. The authors used the correlation between the AMV and the SSL Ti record to reconstruct the AMV over the past 2,900 years with annual resolution. The authors' reconstruction agreed with paleoceanographic proxy records of sea surface temperatures from across the North Atlantic. The record indicates that the warmest interval in the past 2,900 years occurred within the past decade, according to the authors.
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Article #20-14166: "Annually resolved Atlantic sea surface temperature variability over the past 2,900 y," by Francois Lapointe et al.
MEDIA CONTACT: Francois Lapointe, University of Massachusetts Amherst, MA; tel: 413-230-9867; e-mail: <flapointe@umass.edu>
Journal
Proceedings of the National Academy of Sciences