Paired coral Sr/Ca and δ18O records from the Chagos Archipelago: Late twentieth century warming affects rainfall variability in the tropical Indian Ocean

Abstract

Research Article| December 01, 2006 Paired coral Sr/Ca and δ18O records from the Chagos Archipelago: Late twentieth century warming affects rainfall variability in the tropical Indian Ocean Miriam Pfeiffer; Miriam Pfeiffer 1Leibniz Institut für Meereswissenschaften, IFM-GEOMAR, Wischhofstrasse 1-3, 24148 Kiel, Germany Search for other works by this author on: GSW Google Scholar Oliver Timm; Oliver Timm 2International Pacific Research Center, University of Hawaii, POST Building 413, 1680 East West Road, Honolulu, Hawaii 96822, USA Search for other works by this author on: GSW Google Scholar Wolf-Christian Dullo; Wolf-Christian Dullo 3Leibniz Institut für Meereswissenschaften, IFM-GEOMAR, Wischhofstrasse 1-3, 24148 Kiel, Germany Search for other works by this author on: GSW Google Scholar Dieter Garbe-Schönberg Dieter Garbe-Schönberg 4Institut für Geowissenschaften, Ludewig-Meyn-Strasse 10, 24118 Kiel, Germany Search for other works by this author on: GSW Google Scholar Geology (2006) 34 (12): 1069–1072. https://doi.org/10.1130/G23162A.1 Article history received: 04 Jul 2006 rev-recd: 26 Jul 2006 accepted: 27 Jul 2006 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Miriam Pfeiffer, Oliver Timm, Wolf-Christian Dullo, Dieter Garbe-Schönberg; Paired coral Sr/Ca and δ18O records from the Chagos Archipelago: Late twentieth century warming affects rainfall variability in the tropical Indian Ocean. Geology 2006;; 34 (12): 1069–1072. doi: https://doi.org/10.1130/G23162A.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Understanding the relationship between sea surface temperature (SST) and precipitation is a significant challenge for climate models, particularly for the tropics. Here we present a new monthly coral Sr/Ca record from the tropical Indian Ocean (Chagos Archipelago) that extends from 1950 to 1995. The coral Sr/Ca ratio shows a stationary relationship with local SST, and documents a warming of 0.3 °C since 1950. Previous work has shown that the δ18O values measured in the same coral core provide a proxy record of precipitation in the tropical Indian Ocean. The coral δ18O record shows a nonstationary relationship with local SST, and a correlation between δ18O and SST only emerges in the 1970s. It was proposed that this nonstationary behavior is due to an increase in mean SSTs in the tropical Indian Ocean. During the 1970s, SSTs reached a critical threshold (28.5 °C) beyond which small SST anomalies can have a significant impact on atmospheric convection. As a result, the covariance between SST and precipitation in the tropical Indian Ocean increased. Our new Sr/Ca data confirm that the warming of the Indian Ocean during the late twentieth century affects atmospheric convection and rainfall variability. Moreover, our proxy data show that the relationship between SST and precipitation is nonlinear and characterized by threshold behavior. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.