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计过去海面盐度的新方法。随着气候变化，盐度用于理解海洋和大气条件。它还允许科学家预测将来气候如何变化。大西洋的初步研究表明，随着盐度的增加，浮游生物的微小壳中的钠增加。该项目将扩大研究范围，包括大西洋，太平洋和印度洋。为了提高校准的准确性，该项目还将研究壳在下沉到海底时部分溶解的钠如何失去钠。改进的测量将在长时间的沉积物芯上测试，而不是最后一个冰河时代。该项目将支持本科和研究生的教育和专业发展。 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 rubber, from a suite of sediment core tops spanning the subtropical/tropical Atlantic, Pacific, and Indian Oceans.根据九个大西洋核心顶部的初始结果，盐度是控制杆菌中壳Na/Ca比的主要因素。但是，最初的校准需要在各种盐分和其他海洋鲈鱼中扩展。由于在所有位置的动植物组合中，扫描杆菌并不总是很丰富，因此该项目还将为G.橡胶开发校准，G。Rubber是一种比抗囊菌的较浅栖息地的物种，该物种比在研究中通常使用的囊菌栖息地更浅，该物种在研究中通常使用，该研究重建了海面温度（SST）和盐度。因此，该项目的主要目标是开发可在任何位置使用的物种特定的全球校准。该项目还将调查和量化溶解对大西洋和印度洋中壳Na/CA比的影响，因为最近发表的研究表明，溶解度显着影响热带太平洋中的壳Na/Ca比。这将通过测量来自热带大西洋和南印度洋的下坡核心上衣来实现。最后，新开发的校准将用于在海洋同位素阶段3期间在海湾流中基于Na/ca的盐度变化的高分辨率记录，并根据使用MG/CA-SST与G. Rubber中的18O值结合的18oseawater的计算，将其与先前发表的盐度记录进行比较。该项目将支持本科和研究生的教育和专业发展。该项目还将制作旨在向公众教育重要气候变化问题的专业质量YouTube视频。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响审查标准，被认为是通过评估而被视为珍贵的支持。