Evolution of South Pacific Oxygen and Preformed Nutrient Changes over the Deglaciation

冰消期南太平洋氧气的演变和营养盐的变化

基本信息

批准号：
1851900
负责人：
Jean Lynch-Stieglitz
金额：
$ 38.47万
依托单位：
Georgia Tech Research Corporation
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-04-01 至 2024-03-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1851900&HistoricalAwards=false
关键词：
Evolution South Pacific Oxygen Preformed

项目摘要

Oxygen concentrations in the deep ocean, in combination with measurements of nutrients and seawater temperature, provide a powerful constraint for the understanding cycling of carbon in the ocean and the amount of atmospheric carbon dioxide. This research uses deep sea sediment cores as recorders of changes in these key environmental variables since the peak of the last ice age, a period encompassing a fundamental shift in the Earth's climate system. Funding supports training of a graduate student, along with a K-12 teacher and two of her high school students. The training activities will also include the participation of members of under-represented groups who have demonstrated interest in the Ocean Sciences. The data will be made available to the community and will be of broad interest to those seeking to understand the cycling of carbon in the ocean.More specifically, this research will further develop a promising method for the quantitative reconstruction of oxygen in the deep ocean-- the difference between carbon isotope values of epibenthic and deep infaunal foraminifera (Dd13C). Using this technique, the research team will generate records of oxygen concentrations in the South Pacific over the last 25,000 years. This time period covers a major climatic transition when atmospheric carbon dioxide concentrations rose from the low levels of glacial times to the higher values of the pre-industrial present. Estimates bottom water phosphate (using Cd/Ca in benthic foraminifera) and bottom water temperature (using Mg/Ca and Li/Ca in benthic foraminifera) will be made using in the same sediment cores. Combined with the oxygen reconstructions, phosphate and temperature information will be used to estimate the nutrient content in the regions where the deep water left the surface (preformed nutrients). The timing and magnitude of the changes in oxygen and preformed nutrients will help to understand how changes in ocean biology and circulation contributed to the lowering in carbon dioxide during the last ice age.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.

深海中的氧气浓度，结合养分和海水温度的测量，为理解海洋中碳循环的循环和大气二氧化碳量提供了有力的限制。这项研究使用深海沉积物核心作为自上次冰河时代高峰以来这些关键环境变量变化的录音机，这是一个涵盖地球气候系统基本转变的时期。资金支持研究生的培训，以及K-12老师和两名高中生的培训。培训活动还将包括对海洋科学表现出兴趣的代表性不足群体的参与。该数据将提供给社区，并为寻求了解海洋碳循环的人提供广泛的兴趣。更具体地说，这项研究将进一步开发出一种有希望的方法，用于对深海中氧气的定量重建 - 碳同位素值的差异和深层造菌菌群和深度菌孔（DD13C）之间的差异。使用这项技术，研究小组将在过去25，000年中生成南太平洋氧气浓度的记录。当大气中的二氧化碳浓度从低水平的冰川时代升至较高的工业前的二氧化碳浓度时，这段时间涵盖了主要的气候过渡。将在相同的沉积物核中估算底部磷酸盐（在底栖有孔虫中使用CD/CA）和底部水温（使用Mg/ca和Li/Ca）。结合氧气重建，磷酸盐和温度信息将用于估计深水离开表面（预先形成的养分）的区域中的养分含量。氧气和预先形成的营养变化的时间和大小将有助于了解上一个冰河时代期间二氧化碳降低的海洋生物学和循环的变化如何反映了NSF的法定任务，并被认为是通过基金会的知识分子的知识和更广泛的影响来评估的支持，并被认为是值得的。