@article{e5dd2dba0550414c8f2e6279396a6a59,
title = "Improved calibration of the Sr/Ca-temperature relationship in the sclerosponge Ceratoporella nicholsoni: Re-evaluating Sr/Ca derived records of post-industrial era warming",
abstract = "Although the Sr/Ca ratio in the skeletons of sclerosponges appears to be robustly correlated with water temperature, the measurement of Sr/Ca ratios from several specimens by different workers yields unexpectedly large (up to 5 °C) increases in temperature over the past 150 years. This is considerably greater than spatially and temporally averaged observational temperature increases. One possible culprit for the larger than anticipated temperature changes in these samples arises from the calibration between temperature and Sr/Ca ratios of the skeleton that was derived from specimens grown in a relatively narrow range of high temperatures (26 to 30 °C). In order to improve the calibration, we acquired a number of samples of sclerosponges collected at lower average water temperatures (different localities and deeper water depths), and combined measurements of the Sr/Ca ratios from bulk samples representing the last ~15 years of growth with the previous calibration dataset. Analyses of these samples have produced a revised relationship between temperature and Sr/Ca ratios in the skeletons of sclerosponges. Application of this new calibration equation to published sclerosponge data reduces the magnitude of the increase in temperature reconstructed from Sr/Ca ratios to values in better agreement with spatially and temporally gridded observational ocean temperature data sets. However, the acceleration of warming indicated by nearly all Caribbean sclerosponge records over the last several decades remains unchanged by this revised calibration.",
keywords = "Calibration, Ocean temperature, Paleoceanography, Proxy, Sclerosponge, Sr/Ca ratios",
author = "Waite, {Amanda J.} and Swart, {Peter K.} and Rosenheim, {Brad E.} and Rosenberg, {Angela D.}",
note = "Funding Information: We would like to thank Philippe Willenz for aiding species identification of HBOI specimens and Sean Murray and Amel Saied for help in the laboratory. We thank M. Grammer, R. N. Ginsburg, and D. McNeill for assistance with sclerosponge collection in Exuma Sound under NOAA National Undersea Research Program grant 95-340044, and also appreciate sclerosponge contributions from HBOI that were made by Amy Wright, John Reed, and Shirley Pomponi, and colleague Joseph Pawlik. We further acknowledge the countries from which samples were collected, The Commonwealth of The Bahamas and Jamaica. This work was supported by the National Science Foundation [OCE 9819147 and OCE 0823636 ] awards to P. K. Swart. Funding Information: We would like to thank Philippe Willenz for aiding species identification of HBOI specimens and Sean Murray and Amel Saied for help in the laboratory. We thank M. Grammer, R. N. Ginsburg, and D. McNeill for assistance with sclerosponge collection in Exuma Sound under NOAA National Undersea Research Program grant 95-340044, and also appreciate sclerosponge contributions from HBOI that were made by Amy Wright, John Reed, and Shirley Pomponi, and colleague Joseph Pawlik. We further acknowledge the countries from which samples were collected, The Commonwealth of The Bahamas and Jamaica. This work was supported by the National Science Foundation [OCE 9819147 and OCE 0823636] awards to P. K. Swart. Publisher Copyright: {\textcopyright} 2018 Copyright: Copyright 2018 Elsevier B.V., All rights reserved.",
year = "2018",
month = jun,
day = "5",
doi = "10.1016/j.chemgeo.2018.03.005",
language = "English (US)",
volume = "488",
pages = "56--61",
journal = "Chemical Geology",
issn = "0009-2541",
publisher = "Elsevier",
}