Developing a New Paleosalinity Proxy Based on Na/Ca Ratios in the Planktonic Foraminifera Trilobatus sacculifer and Globigerinoides ruber

基于浮游有孔虫 Trilobatus sacculifer 和 Globigerinoides ruber 中 Na/Ca 比率开发新的古盐度代理

• 批准号: 2143007
• 负责人: Matthew Schmidt
• 金额: $ 32.02万
• 依托单位: Old Dominion University Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-15 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2143007&HistoricalAwards=false
• 关键词: Developing; New; Paleosalinity; Proxy; Based

This project will develop a new method of estimating past ocean surface salinity. Salinity is used to understand ocean and atmospheric conditions as climate changes. It also allows scientists to predict how the climate will change in the future. Preliminary studies in the Atlantic Ocean show that sodium increases in the tiny shells of plankton as the salinity increases. This project will expand the range of study to include the Atlantic, Pacific, and Indian Oceans. To improve the accuracy of the calibration, this project will also study how the shells lose sodium as they partially dissolved when sinking to bottom of the ocean. The improved measurement will be tested on long sediment cores than span the last ice age. This project will support the educational and professional development of undergraduate and graduate students. The project will also produce professional quality YouTube videos aimed at educating the public on important climate change issues.This project will develop a new upper ocean paleosalinity proxy based on Na/Ca ratios in two species of planktic foraminifera, Trilobatus sacculifer and Globigerinoides ruber, from a suite of sediment core tops spanning the subtropical/tropical Atlantic, Pacific, and Indian Oceans. Based on initial results from nine Atlantic core tops, salinity is the dominant factor controlling shell Na/Ca ratios in T. sacculifer. However, the initial calibration needs to be expanded across a wider range of salinities and in other ocean basins. Because T. sacculifer is not always abundant in faunal assemblage at all locations, this project will also develop a calibration for G. ruber, a species with an even shallower depth habitat than T. sacculifer that is commonly utilized in studies reconstructing sea surface temperature (SST) and salinity. The major goal of this project, therefore, is to develop species-specific global calibrations that can be used at any location. This project will also investigate and quantify the effects of dissolution on shell Na/Ca ratios in the Atlantic and Indian Oceans, as a recently published study showed that dissolution significantly impacts shell Na/Ca ratios in the tropical Pacific. This will be achieved by measuring down-slope core tops from the tropical Atlantic and the south Indian Ocean. Finally, the newly developed calibrations will be used to generate a high-resolution record of Na/Ca-based salinity change in the Gulf Stream during Marine Isotope Stage 3 and compare it to a previously published salinity record based on the calculation of 18Oseawater using Mg/Ca-SST combined with 18O values in G. ruber. This project will support the educational and professional development of undergraduate and graduate students. The project will also produce professional quality YouTube videos aimed at educating the public on important climate change issues.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目将开发一种估算过去海洋表面盐度的新方法，用于了解气候变化时的海洋和大气状况。初步研究表明，大西洋的气候将如何变化。随着盐度的增加，浮游生物微小贝壳中的钠含量也会增加。该项目将把研究范围扩大到大西洋、太平洋和印度洋。为了提高校准的准确性，该项目还将研究贝壳如何失去钠。作为当沉入海底时，它们会部分溶解。该项目将在比上一个冰河时代更长的沉积物岩心上进行测试，该项目还将支持本科生和研究生的教育和专业发展。 YouTube 视频旨在教育公众了解重要的气候变化问题。该项目将根据两种浮游有孔虫 Trilobatus sacculifer 和 Globigerinoides ruber 的 Na/Ca 比率开发一种新的上层海洋古盐度代理。横跨亚热带/热带大西洋、太平洋和印度洋的沉积物核心顶部套件基于九个大西洋核心顶部的初步结果，盐度是控制 T. sacculifer 壳 Na/Ca 比率的主要因素。由于 T. sacculifer 在所有地点的动物群落并不总是丰富，因此该项目还将开发 G. sacculifer 的校准。 ruber 是一种栖息地深度比 T. sacculifer 更浅的物种，常用于重建海面温度 (SST) 和盐度的研究。因此，该项目的主要目标是开发可用于特定物种的全球校准。该项目还将调查和量化溶解对大西洋和印度洋贝壳钠/钙比的影响，最近发表的一项研究表明，溶解对热带太平洋贝壳钠/钙比有显着影响。是通过测量热带大西洋和南印度洋的下坡核心顶部来实现最后，新开发的校准将用于生成海洋同位素阶段墨西哥湾流中基于钠/钙的盐度变化的高分辨率记录。 3 并将其与之前发布的盐度记录进行比较，该记录基于使用 Mg/Ca-SST 与 G. ruber 中的 18O 值计算的 18O 海水。该项目将支持教育。该项目还将制作专业品质的 YouTube 视频，旨在教育公众了解重要的气候变化问题。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优势和能力进行评估，认为值得支持。更广泛的影响审查标准。