Data Synthesis and Evaluation of the Salinity Influence on Mg/Ca Paleothermometry in the Low Latitudes

有孔虫的镁钙比（Mg/Ca）是研究过去海洋温度的重要和广泛使用的工具。最近的研究表明，盐度的变化可能有更大的影响镁/钙古温度比以前认为，古温度数据的解释具有重大意义。然而，这种影响的程度仍在争论之中。这项由加州大学圣巴巴拉分校的研究人员领导的拟议工作旨在通过三管齐下的方法来解决这一问题，以量化盐度对有孔虫Mg/Ca的影响：1）分析来自三个具有大盐度梯度的地区的沉积物陷阱和岩心顶部样品（阿拉伯海、孟加拉湾和非洲西北部）; 2）低纬度可用沉积物收集器、岩心顶部和浮游生物拖曳数据的综合;高盐度区次生成岩作用对有孔虫Mg/Ca的影响。将使用比较和多变量技术来评估相对于其他已知影响的盐度影响的大小（例如，这项研究将提高对重建过去温度的信心，从而提高对气候敏感性模型评估的信心。开发一个可搜索的有孔虫Mg/Ca数据库将促进知识和数据共享。该项目将一名高级教员与一名代表性不足的初级教员组成一个小组，并将为一名博士后研究人员提供支持。

Foraminiferal magnesium to calcium ratios (Mg/Ca) are an important and widely used tool in studies of past ocean temperatures. Recent research suggests that variations in salinity could have a greater influence on Mg/Ca paleothermometry than previously believed, with significant implications for interpretations of paleotemperature data. The magnitude of that influence, however, remains under debate. The proposed work, led by researchers at UC Santa Barbara, aims to resolve this problem using a three-pronged approach to quantify the influence of salinity on foraminiferal Mg/Ca: 1) analysis of sediment trap and core-top samples from three regions with large salinity gradients (Arabian Sea, Bay of Bengal, and northwest Africa); 2) synthesis of available sediment trap, core-top, and plankton tow data from low latitudes; and 3) assessment of secondary diagenetic effects on foraminiferal Mg/Ca in high-salinity regions. Comparative and multivariate techniques will be used to evaluate the magnitude of the salinity influence relative to other known influences (e.g., temperature, seasonality, seafloor dissolution) on foraminiferal Mg/Ca.This research will lead to increased confidence in reconstructions of past temperature and, consequently, in model assessments of climate sensitivity. Knowledge and data sharing will be facilitated by the development of a searchable foraminiferal Mg/Ca database. The project will team a senior faculty member with a junior faculty member who is a member of an underrepresented group, and will provide support for a post-doctoral researcher.