Tracing Past Methane Variations with Stable Isotopes in Antarctic Ice Cores

GSTDTAP

项目编号	1745078
	Tracing Past Methane Variations with Stable Isotopes in Antarctic Ice Cores
	Edward Brook
主持机构	Oregon State University
项目开始年	2018
	2018-08-01
项目结束日期	2022-07-31
资助机构	US-NSF
项目类别	Continuing grant
项目经费	359228(USD)
国家	美国
语种	英语
英文摘要	This project will develop methods to measure the ratios of carbon-13 to carbon-12, and heavy to light hydrogen in methane in air trapped in ice cores. The ratios of the different forms of carbon and hydrogen are "fingerprints" of different sources of this gas in the past--for example wetlands in the tropics versus methane frozen in the sea floor. Once the analysis method is developed, the measurements will be used to examine why methane changed abruptly in the past, both during the last ice age, and during previous warm periods. The data will be used to understand how methane sources like wildfires, methane hydrates, and wetlands respond to climate change. This information is needed to understand future risks of large changes in methane in the atmosphere as Earth warms. The project involves two tasks. First, the investigators will build and test a gas extraction system for methane isotopic measurements using continuous flow methods, with the goal of equaling or bettering the precision attained by the few other laboratories that make these measurements. The system will be interfaced with existing mass spectrometers at Oregon State University. The system consists of a vacuum chamber and sequence of traps, purification columns, and furnaces that separate methane from other gases and convert it to carbon dioxide or hydrogen for mass spectrometry. Second, the team will measure the isotopic composition of methane across large changes in concentration associated with two past interglacial periods and during abrupt methane changes of the last ice age. These measurements will be used to understand if the main reason for these concentration changes is climate-driven changes in emissions from wetlands, or whether other sources are involved, for example methane hydrates or wildfires. 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.
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/72996
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Edward Brook.Tracing Past Methane Variations with Stable Isotopes in Antarctic Ice Cores.2018.