EMBRACE-AGS-Seed: Decadal Trends of Atmospheric Ethane - Building Capacity for Trace Gas Analysis and Modeling at Portland State University

这个“拥抱种子”项目的重点是研究大气中当前和历史上的乙烷和甲烷浓度。这些物种的氧化有助于臭氧和二次有机气溶胶的产生，并影响大气的氧化能力。这项研究工作利用了俄勒冈州研究生院(OGI)20世纪80年代初收集的大气乙烷测量数据的未出版档案，并将包括1978-1998年期间在俄勒冈州米尔斯角收集的空气样本中乙烷的新分析。该项目将有助于更好地了解大气中乙烷和甲烷的分布和历史趋势，以及它们对空气质量和气候的重大影响。研究包括三个主要活动：(1)利用美国国家海洋和大气局碳循环温室气体小组最近的地表烧瓶乙烷测量，对20世纪80年代初来自OGI全球监测网络的历史乙烷观测数据进行相互校准；(2)定制用于乙烷模拟的GEOS-Chem高性能大气化学模型；(3)在两个时期内对乙烷进行反向模拟研究，该研究涵盖了20世纪80年代至21世纪头10年气体浓度急剧下降的两个时期。由于乙烷与羟基自由基(OH)发生反应，它间接影响大气中许多其他痕量气体的寿命，包括甲烷(CH4)。这项研究将使研究人员能够探索乙烷来源在十年尺度上的变化，并开发新的研究项目，利用乙烷和甲烷的浓度及其同位素作为石油和天然气释放的示踪剂，以及野火和生物质燃烧产生的排放。这项种子计划将有助于建立波特兰州立大学(PSU)乙烷和非甲烷碳氢化合物气体研究的能力。PIS计划利用这项种子研究的结果来制定一项完整的建议，以进行未来使用乙烷和甲烷及其同位素的多重示踪研究，以量化来自自然和人为来源的这些气体的通量。这一奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

This EMBRACE SEED project is focused on the study of current and historic ethane and methane concentrations in the atmosphere. Oxidation of these species contributes to production of ozone and secondary organic aerosol and affects the oxidizing capacity of the atmosphere. This research effort makes use of an unpublished archive at the Oregon Graduate Institute (OGI) of atmospheric ethane measurements collected in the early 1980s and will include new analyses for ethane in air samples collected during the period 1978–1998 at Cape Meares, Oregon. This project will lead to a better understanding of the distributions and historical trends of atmospheric ethane and methane and their significant impact on both air quality and climate.The research includes three primary activities: (1) Intercalibration of historic ethane observations from the OGI global monitoring network in the early 1980s with recent surface flask ethane measurements from the NOAA Carbon Cycle Greenhouse Gas Group; (2) Customization of the GEOS-Chem High Performance atmospheric chemistry model for ethane simulations; and (3) Inverse modeling studies of ethane within two periods that bracket the steep decline in concentrations of the gas from the 1980s to the 2000s. Due to its reaction with the hydroxyl radical (OH), ethane indirectly influences the lifetimes of many other trace gases in the atmosphere including methane (CH4). This research will enable the investigators to probe changes in the sources of ethane over decadal scales and develop new research projects that make use of the concentrations of both ethane and methane and their isotopes as tracers of oil and natural gas releases, as well emissions from wildfire and biomass burning.This seed proposal will help build research capacity for ethane and non-methane hydrocarbon gas research at Portland State University (PSU). The PIs plan to use the results from this SEED study to develop a full proposal to conduct future multi-tracer studies using ethane and methane and their isotopes to quantify the fluxes of these gases from natural and anthropogenic sources.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.