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

低纬度盐度对 Mg/Ca 古温度影响的数据综合与评价

• 批准号: 1260696
• 负责人: Syee Weldeab
• 金额: $ 33.66万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1260696&HistoricalAwards=false
• 关键词: Data; Synthesis; Evaluation; Salinity; Influence

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.

有孔虫镁钙比（Mg/Ca）是研究过去海洋温度的一个重要且广泛使用的工具。最近的研究表明，盐度变化对Mg/Ca古测温的影响可能比以前认为的更大，这对古温度数据的解释具有重要意义。然而，这种影响的程度仍存在争议。由加州大学圣巴巴拉分校（UC Santa Barbara）的研究人员领导的这项拟议的工作旨在通过三管齐下的方法来解决这个问题，以量化盐度对有孔虫Mg/Ca的影响：1)分析来自三个盐度梯度较大的地区（阿拉伯海、孟加拉湾和非洲西北部）的沉积物陷阱和岩心顶部样本；2)低纬度可用沉积物捕集器、岩心顶部和浮游生物拖曳资料的综合；3)高盐度地区有孔虫Mg/Ca的次生成岩作用评价。将使用比较和多变量技术来评估盐度相对于其他已知影响（如温度、季节性、海底溶解）对有孔虫Mg/Ca的影响程度。这项研究将提高对过去温度重建的信心，从而提高对气候敏感性的模式评估。开发可检索的有孔虫镁/钙数据库将促进知识和数据共享。该项目将由一名高级教员和一名代表不足的初级教员组成，并将为一名博士后研究员提供支持。