Synchroneity of Tropical and High-Latitude Atlantic Temperatures over the Last Glacial Termination

Varved sediments from Cariaco Basin core PL07-39PC
Sediment varves from the Younger Dryas interval of core PL07-39PC. Click for larger image of the interval between ~11,900 to 12,200 y BP. Photo by Rusti Lotti, Lamont-Doherty Earth Observatory of Columbia University.
Synchroneity of Tropical and High-Latitude Atlantic Temperatures over the Last Glacial Termination
Science
Volume 301, Number 5638, pp.1361-1364, 5 September 2003

David W. Lea and Dorothy K. Pak
Department of Geological Sciences and Marine Science Institute, University of California, Santa Barbara, CA 93106, USA.

Larry C. Peterson
Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA.

Konrad A. Hughen
Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.

ABSTRACT:
A high-resolution western tropical Atlantic sea surface temperature (SST) record from the Cariaco Basin on the northern Venezuelan shelf, based on Mg/Ca values in surface-dwelling planktonic foraminifera, reveals that changes in SST over the last glacial termination are synchronous, within ±30 to ±90 years, with the Greenland Ice Sheet Project 2 air temperature proxy record and atmospheric methane record. The most prominent deglacial event in the Cariaco record occurred during the Younger Dryas time interval, when SSTs dropped by 3° to 4°C. A rapid southward shift in the atmospheric intertropical convergence zone could account for the synchroneity of tropical temperature, atmospheric methane, and high-latitude changes during the Younger Dryas.

DATA:
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Cariaco Basin foraminiferal Mg/Ca and SST reconstruction
Climate proxy data from Cariaco Basin core PL07-39PC Figure 1. Climate proxy data from Cariaco Basin core PL07-39PC (10°42.00'N, 64°56. 50'W, 790 m). The Mg/Ca record is from planktonic foraminifera G. ruber, white variety, with the pink variety analyzed when sample abundances were limited. Each point is the average of one to five replicates; the pooled SD of all replicate analyses (df = 155) was ±0.16 mmom/mol (±4%). Oxygen isotope data are from G. ruber, white variety. Sedimentary grayscale data are from Hughen et al. 1998. The gap between 165 and 192 cm is due to a turbidite. Core PL07-39PC has nearly continuous laminations from 0 to 630 cm; the transition to bioturbated sediments occurs at the Bølling transition.

To read or view the full study, please visit the Science website.
It was published in Science Volume 301, Number 5638, pp.1361-1364, 5 September 2003

Supported by NSF (grant OCE0117886). The Guggenheim and Leverhulme Foundations and a Clare Hall Visiting Fellowship provided support for D.W.L. at Cambridge University in 2002–2003.


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10 October 2003