Deglacial sea surface temperatures of the western tropical Pacific : a new look at old coral
Cohen, Anne L.
Hart, Stanley R.
MetadataShow full item record
KeywordTropical Pacific; Sea surface temperature; Bølling-Allerod; Coral Sr/Ca; Ion microprobe; Diagenesis
Using Secondary Ion Mass Spectrometry (SIMS) ion microprobe techniques, we generated annual Sr/Ca cycles with subweekly resolution from chunks of Porites coral retrieved from a Tahiti barrier reef drill core (149°W, 17°S), representing the period 13,650 to 13,100 years B.P. The centers of pristine skeletal septa were selectively targeted with a 10 μm diameter ion beam spot, avoiding adjacent pore spaces occupied by secondary aragonite needles. Applying a Sr/Ca–sea surface temperature (SST) calibration equation derived from modern Tahiti Porites having the same low growth rate as the fossil specimens, we obtained SSTs ∼0.5°–1.5°C cooler during the Bølling-Allerod relative to the present day, with no significant change in seasonality. On the contrary, we estimate that analysis of bulk samples would yield excessively cool Sr/Ca-based SST estimates due to the occupation by secondary aragonite crystals of up to 50% of the skeletal pore space in the ancient samples. We find that growth rate effects on coral Sr/Ca further depress the apparent mean annual derived SSTs (by >3°C) and amplify the apparent seasonality by selectively enhancing wintertime cooling. Our microscale analysis of pristine skeleton and application of an appropriate growth-dependent calibration yield Sr/Ca-derived SSTs that are in good agreement with those derived from Mg/Ca ratios of calcitic foraminifera which indicate a continuous postglacial warming of the western tropical Pacific, in phase with the warming of the tropical Atlantic.
Author Posting. © American Geophysical Union, 2004. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 19 (2004): PA4031, doi:10.1029/2004PA001084.
Showing items related by title, author, creator and subject.
Tierney, Jessica E.; Abram, Nerilie J.; Anchukaitis, Kevin J.; Evans, Michael N.; Giry, Cyril; Kilbourne, K. Halimeda; Saenger, Casey P.; Wu, Henry C.; Zinke, Jens (John Wiley & Sons, 2015-03-18)Most annually resolved climate reconstructions of the Common Era are based on terrestrial data, making it a challenge to independently assess how recent climate changes have affected the oceans. Here as part of the Past ...
Role of net surface heat flux in seasonal variations of sea surface temperature in the tropical Atlantic Ocean Yu, Lisan; Jin, Xiangze; Weller, Robert A. (American Meteorological Society, 2006-12-01)The present study used a new net surface heat flux (Qnet) product obtained from the Objective Analyzed Air–Sea Fluxes (OAFlux) project and the International Satellite Cloud Climatology Project (ISCCP) to examine two specific ...
Record of Little Ice Age sea surface temperatures at Bermuda using a growth-dependent calibration of coral Sr/Ca Goodkin, Nathalie F.; Hughen, Konrad A.; Cohen, Anne L.; Smith, Struan R. (American Geophysical Union, 2005-11-30)Strontium to calcium ratios (Sr/Ca) are reported for a massive brain coral Diploria labyrinthiformis collected from the south shore of Bermuda and are strongly correlated with both sea surface temperature (SST) and mean ...