@article{9f17bf4659f04eeaa223aeb922c774ff,
title = "Fidelity of the Coral Sr/Ca Paleothermometer Following Heat Stress in the Northern Gal{\'a}pagos",
abstract = "Coral Sr/Ca records have been widely used to reconstruct and understand past sea surface temperature (SST) variability in the tropical Pacific. However, in the eastern equatorial Pacific, coral growth conditions are marginal, and strong El Ni{\~n}o events have led to high mortality, limiting opportunities for coral Sr/Ca-based SST reconstructions. In this study, we present two ∼25-year Sr/Ca and Mg/Ca records measured on modern Porites lobata from Wolf and Darwin Islands in the northern Gal{\'a}pagos. In these records, we confirm the well-established relationship between Sr/Ca and SST and investigate the impact of heat stress on this relationship. We demonstrate a weakened relationship between Sr/Ca and SST after a major (Degree Heating Months 9°C-months) heat stress event during the 1997–1998 El Ni{\~n}o, with a larger response in the Wolf core. However, removing data that covers the 1997–1998 El Ni{\~n}o from calibration does not improve reconstruction statistics. Nevertheless, we find that excluding data after the 1997–1998 El Ni{\~n}o event from the calibration reduces the SST reconstruction error slightly. These results confirm that coral Sr/Ca is a reliable SST proxy in this region, although it can respond adversely to unusual heat stress. We suggest that noise in Sr/Ca-SST calibrations may be reduced by removing data immediately following large heat extremes.",
keywords = "ENSO, coral Sr/Ca, coral geochemistry, eastern equatorial Pacific, heat stress",
author = "Cheung, {Anson H.} and Cole, {Julia E.} and Thompson, {Diane M.} and Lael Vetter and Gloria Jimenez and Tudhope, {Alexander W.}",
note = "Funding Information: The authors are grateful to the Parque Nacional Gal{\'a}pagos for permission and support to work in this very special place, and to the Charles Darwin Research Station for facilitating this project. Field sampling was enabled by the crew of the Queen Mabel and her captain Eduardo Rosero. Roberto Pepolas particularly improved our local understanding, coring efficiency, and safety over multiple field seasons. The authors also thank Jenifer Suarez, Meriwether Wilson, Diego Ruiz, Colin Chilcott, Jorge Baque, and Stephan Hlohowskyj for tireless field assistance and expertise. The authors thank Corey Shaver for her help in laboratory analysis, Emma Reed and Kelsey Dyez for helpful comments and suggestions, and Juan Pablo D'Olivo for the Rayleigh fractionation equation MATLAB code. This work was supported by NSF grants 1401326/1829613 and 0957881 to JEC, and by the University of Arizona Honors College Alumni Legacy Grant (Honors Thesis) and Brown University Presidential Fellowship to AHC. This publication is contribution #2415 of the Charles Darwin Foundation for the Gal{\'a}pagos Islands. Funding Information: The authors are grateful to the Parque Nacional Gal?pagos for permission and support to work in this very special place, and to the Charles Darwin Research Station for facilitating this project. Field sampling was enabled by the crew of the Queen Mabel and her captain Eduardo Rosero. Roberto Pepolas particularly improved our local understanding, coring efficiency, and safety over multiple field seasons. The authors also thank Jenifer Suarez, Meriwether Wilson, Diego Ruiz, Colin Chilcott, Jorge Baque, and Stephan Hlohowskyj for tireless field assistance and expertise. The authors thank Corey Shaver for her help in laboratory analysis, Emma Reed and Kelsey Dyez for helpful comments and suggestions, and Juan Pablo D'Olivo for the Rayleigh fractionation equation MATLAB code. This work was supported by NSF grants 1401326/1829613 and 0957881 to JEC, and by the University of Arizona Honors College Alumni Legacy Grant (Honors Thesis) and Brown University Presidential Fellowship to AHC. This publication is contribution #2415 of the Charles Darwin Foundation for the Gal?pagos Islands. Publisher Copyright: {\textcopyright} 2021. American Geophysical Union. All Rights Reserved.",
year = "2021",
month = dec,
doi = "10.1029/2021PA004323",
language = "English (US)",
volume = "36",
journal = "Paleoceanography and Paleoclimatology",
issn = "2572-4517",
publisher = "American Geophysical Union",
number = "12",
}