Accurate estimation of sea surface temperatures using dissolution‐corrected calibrations for Mg/Ca paleothermometry
Accurate estimation of sea surface temperatures using dissolution‐corrected calibrations for Mg/Ca paleothermometry
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DOI：
10.1029/2001pa000749
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发表时间：
2002-09
期刊：
影响因子：
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通讯作者：
Y. Rosenthal;G. P. Lohmann
中科院分区：
文献类型：
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作者：
Y. Rosenthal;G. P. Lohmann
[1]在同一有孔虫壳体上进行的成对δ18O和镁/钙测量提供了独立估计海表面温度变化的能力，并评估了它们与大陆冰盖消长的时间关系。然而，由于缺乏一种定量方法来校正溶解蚀变的镁钙记录，这一方法的准确性受到了混淆。在这里，我们描述了镁/钙古温度计的溶解校正定标，其中预指数常数是大小归一化壳重的函数：(1)对于红色棉(212300wt M)(镁/钙)Ruber=(0.025 wt+0.11)e0.095T；(B)对于球囊棉(355-425μm)(镁/钙)Scc=(0.0032 wt+0.181)e0.095T。新的校准提高了SST估计的准确性，并适用于全球。根据这一修正，最后一次冰盛期赤道东部大西洋海温估计比今天低2.9°±0.4°C。
[1] Paired δ18O and Mg/Ca measurements on the same foraminiferal shells offer the ability to independently estimate sea surface temperature (SST) changes and assess their temporal relationship to the growth and decay of continental ice sheets. The accuracy of this method is confounded, however, by the absence of a quantitative method to correct Mg/Ca records for alteration by dissolution. Here we describe dissolution-corrected calibrations for Mg/Ca-paleothermometry in which the preexponent constant is a function of size-normalized shell weight: (1) for G. ruber (212–300 μm) (Mg/Ca)ruber = (0.025 wt + 0.11) e0.095T and (b) for G. sacculifer (355–425 μm) (Mg/Ca)sacc = (0.0032 wt + 0.181) e0.095T. The new calibrations improve the accuracy of SST estimates and are globally applicable. With this correction, eastern equatorial Atlantic SST during the Last Glacial Maximum is estimated to be 2.9° ± 0.4°C colder than today.