Reduced El Nino-Southern Oscillation during the Last Glacial Maximum

Type Article
Date 2015-01
Language English
Author(s) Ford Heather L.1, 2, Ravelo A. Christina1, Polissar Pratigya J.2
Affiliation(s) 1 : Univ Calif Santa Cruz, Ocean Sci Dept, Santa Cruz, CA 95064, USA.
2 : Lamont Doherty Earth Observ, Palisades, NY 10964, USA.
Source Science (0036-8075) (Amer Assoc Advancement Science), 2015-01 , Vol. 347 , N. 6219 , P. 255-258
DOI 10.1126/science.1258437
WOS© Times Cited 77
Abstract El Nino-Southern Oscillation (ENSO) is a major source of global interannual variability, but its response to climate change is uncertain. Paleoclimate records from the Last Glacial Maximum (LGM) provide insight into ENSO behavior when global boundary conditions (ice sheet extent, atmospheric partial pressure of CO2) were different from those today. In this work, we reconstruct LGM temperature variability at equatorial Pacific sites using measurements of individual planktonic foraminifera shells. A deep equatorial thermocline altered the dynamics in the eastern equatorial cold tongue, resulting in reduced ENSO variability during the LGM compared to the Late Holocene. These results suggest that ENSO was not tied directly to the east-west temperature gradient, as previously suggested. Rather, the thermocline of the eastern equatorial Pacific played a decisive role in the ENSO response to LGM climate.
Full Text
File Pages Size Access
Publisher's official version 5 1 MB Open access
Top of the page