Near collapse of the meridional SST gradient in the eastern equatorial Pacific during Heinrich Stadial 1
Kienast, Stephanie S.
Hill, Paul S.
Mix, Alan C.
MetadataShow full item record
Sea surface temperatures (SST) and inorganic continental input over the last 25,000 years (25 ka) are reconstructed in the far eastern equatorial Pacific (EEP) based on three cores stretching from the equatorial front (~0.01°N, ME0005-24JC) into the cold tongue region (~3.6°S; TR163-31P and V19-30). We revisit previously published alkenone-derived SST records for these sites and present a revised chronology for V19-30. Inorganic continental input is quantified at all three sites based on 230Th-normalized fluxes of the long-lived continental isotope thorium-232 and interpreted to be largely dust. Our data show a very weak meridional (cross-equatorial) SST gradient during Heinrich Stadial 1 (HS1, 18–15 ka B.P.) and high dust input along with peak export production at and north of the equator. These findings are corroborated by an Earth system model experiment for HS1 that simulates intensified northeasterly trade winds in the EEP, stronger equatorial upwelling, and surface cooling. Furthermore, the related southward shift of the Intertropical Convergence Zone (ITCZ) during HS1 is also indicative of drier conditions in the typical source regions for dust.
Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 28 (2013): 663–674, doi:10.1002/2013PA002499.
Suggested CitationArticle: Kienast, Stephanie S., Friedrich, Tobias, Dubois, Nathalie, Hill, Paul S., Timmermann, Axel, Mix, Alan C., Kienast, Markus, "Near collapse of the meridional SST gradient in the eastern equatorial Pacific during Heinrich Stadial 1", Paleoceanography 28 (2013): 663–674, DOI:10.1002/2013PA002499, https://hdl.handle.net/1912/6458
Showing items related by title, author, creator and subject.
Dynamic intermediate ocean circulation in the North Atlantic during Heinrich Stadial 1 : a radiocarbon and neodymium isotope perspective Wilson, David J.; Crocket, Kirsty C.; van de Flierdt, Tina; Robinson, Laura F.; Adkins, Jess F. (John Wiley & Sons, 2014-11-20)The last deglaciation was characterized by a series of millennial-scale climate events that have been linked to deep ocean variability. While often implied in interpretations, few direct constraints exist on circulation ...
Comment on “Do geochemical estimates of sediment focusing pass the sediment test in the equatorial Pacific?” by M. Lyle et al. Francois, Roger; Frank, Martin; Rutgers van der Loeff, Michiel M.; Bacon, Michael P.; Geibert, Walter; Kienast, Stephanie S.; Anderson, Robert F.; Bradtmiller, Louisa I.; Chase, Zanna; Henderson, Gideon M.; Marcantonio, Franco; Allen, Susan E. (American Geophysical Union, 2007-03-06)
Deepwater expansion and enhanced remineralization in the eastern equatorial Pacific during the last glacial maximum Umling, Natalie E.; Thunell, Robert C.; Bizimis, Michael (John Wiley & Sons, 2018-06-04)Published estimates of the radiocarbon content of middepth waters suggest a decrease in ventilation in multiple locations during the last glacial maximum (LGM; 24.0–18.1 ka). Reduced glacial ventilation would have allowed ...