Abstract The Long chain Diol Index (LDI) is a relatively new organic geochemical proxy for sea surface temperature (SST), based on the abundance of the C30 1,15-diol relative to the summed abundance of the C28 1,13-, C30 1,13- and C30 1,15-diols. Here we substantially extend and re-evaluate the initial core top calibration by combining the original dataset with 172 data points derived from previously published studies and 262 newly generated data points. In total, we considered 595 globally distributed surface sediments with an enhanced geographical coverage compared to the original calibration. The relationship with SST is similar to that of the original calibration but with considerably increased scatter. The effects of freshwater input (e.g., river runoff) and long-chain diol contribution from Proboscia diatoms on the LDI were evaluated. Exclusion of core-tops deposited at a salinity https://doi.org/10.1016/j.gca.2012.01.024 ), although with a larger calibration error of 3 °C. This larger calibration error results from several regions where the LDI does not seem to have a strong temperature dependence with annual mean SST, posing a limitation on the application of the LDI.

中文翻译：

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海洋表层沉积物中长链二醇指数的全球温度校准

摘要 长链二醇指数 (LDI) 是一种相对较新的海面温度 (SST) 有机地球化学替代指标，它基于 C30 1,15-二醇的丰度相对于 C28 1,13-, C30 1,13- 和 C30 1,15-二醇。在这里，我们通过将原始数据集与来自先前发表的研究的 172 个数据点和 262 个新生成的数据点相结合，大幅扩展和重新评估初始核心顶部校准。与原始校准相比，我们总共考虑了 595 个全球分布的表层沉积物，其地理覆盖范围有所扩大。与 SST 的关系与原始校准的关系相似，但散射明显增加。评估了淡水输入（例如河流径流）和长链二醇对 LDI 的影响。排除以盐度沉积的核心顶部 https://doi.org/10.1016/j.gca.2012.01.024 ），尽管校准误差更大，为 3 °C。这种较大的校准误差来自几个地区，其中 LDI 似乎与年平均海温没有强烈的温度相关性，从而限制了 LDI 的应用。