Understanding Recent Changes in the Atmospheric Methane Growth Rate through Analyses of the Isotopic Composition of Methane in a Rare Air Archive

该项目的主要目标是通过以下方法更好地了解大气甲烷（CH 4）增长率的近期趋势：（1）使用来自俄勒冈州研究生院（OGI）空气档案馆的样本分析20年来CH 4的同位素组成;（2）从改变CH 4源和汇的角度解释大气CH 4的长期和年际变化。 超过380个样品最初收集在俄勒冈州的米尔斯角（1978-1998年），帕尔默站，南极洲（1991-1997年），和点巴罗，阿拉斯加（1995-1998年）将分析其甲烷同位素组成（13 C/12 C和D/H）。 由此产生的数据集将提供1988年之前唯一的北方半球13 C/12 C时间序列记录，并且在任何情况下都是唯一的月分辨率记录。 同样重要的是，D/H时间序列将是1996年以前的唯一记录。 结果将与更现代的记录合并，创造一个30年的复合记录，并解释CH 4浓度和同位素组成变化的结果，包括生物、化石、和甲烷的热源。通过本项目为波特兰州立大学本科生和研究生提供的前沿研究领域的研究机会将提高他们的为下一代地球科学研究奠定基础。 建立与科学和工程计划的波特兰学徒的伙伴关系，将启动和促进与当地高中学生在夏季指导的关系，并提供了一个框架，传达科学探索的兴奋和挑战，有前途的年轻学生之前，他们致力于在大学的重点领域。

The primary objective of this project is to better understand recent trends in the growth rate of atmospheric methane (CH4) through: (1) analysis of the isotopic composition of CH4 over two decades using samples from the Oregon Graduate Institute (OGI) air archive and (2) the interpretation of long-term and interannual variations in atmospheric CH4 in terms of changing CH4 sources and sinks. More than 380 samples originally collected at Cape Meares, Oregon (1978-1998), Palmer Station, Antarctica (1991-1997), and Point Barrow, Alaska (1995-1998) will be analyzed for their CH4 isotopic composition (13C/12C and D/H). The resulting dataset will provide the only northern hemisphere time series record of 13C/12C available prior to 1988, and the only one at monthly resolution in any case. Equally important, the D/H time series will be the only record available prior to 1996. Results will be merged with more modern records creating a 30 year composite record and interpret the results of the changing concentration and isotopic composition of CH4 in terms of changing biogenic, fossil, and pyrogenic sources of CH4 over this time period.The hands-on research opportunities for Portland State University undergraduate and graduate students provided through this project in an area of cutting edge research will enhance their development and build a foundation for the next generation of Earth science research. Building a partnership with the Portland Apprenticeships in Science and Engineering Program will initiate and foster a relationship of mentoring with local high school students during summers and provide the framework for conveying the excitement and challenges of science exploration to promising young students before they commit to fields of focus in college.