MRI: Development of a Chemical Ionization Mass Spectrometer Using Isotope Dilution for Atmospheric Peroxide Measurements

该项目将开发一种化学电离质谱（CIMS）系统，使用同位素稀释，以10赫兹的时间分辨率原位测定大气中的过氧化物。该仪器将被认证用于包括NSF湾流- v （GV）在内的研究飞机。它将为解决围绕过氧化物大气化学的一些尚未解决的科学问题提供一个新的工具。该仪器的快速响应还将允许对流层中过氧化物的通量研究，大大提高我们对过氧化氢沉积和大陆和海洋边界层中奇氢损失的理解。利用GV平台，该仪器将有助于定量过氧化氢和甲基过氧化氢在对流层上层、平流层下层和热带对流层顶层的分布，并评估其与深层对流相关的运输和化学性质。最后，快速仪器将有足够的响应时间来详细研究影响过氧化物的云过程。由于云的穿透只持续几秒钟，目前的仪器对云的分辨速度太慢，更不用说对亚云过程的分辨了。除了提供一种新的原位测量能力，显著增强未来机载科学任务的化学包外，该项目还将让本科生和博士后学者参与仪器开发，提高他们在大气测量仪器开发方面的研究技能。该博士后学者还将在美国海军学院的教师指导下教授本科化学课程，从而获得宝贵的经验。

This project will develop a chemical ionization mass spectrometry (CIMS) system using isotope dilution for the in situ determination of peroxides in the atmosphere with a 10 Hz time resolution. The instrument will be certified for use on research aircraft including the NSF Gulfstream-V (GV). It will provide a new tool to address a number of unresolved scientific questions surrounding the atmospheric chemistry of peroxides. The fast response of this instrument will also allow flux studies of peroxides in the troposphere, significantly improving our understanding of hydroperoxide deposition and odd-hydrogen loss in the continental and marine boundary layers. Using the GV platform, the instrument will aid in quantifying hydrogen peroxide and methylhydroperoxide distributions in the upper troposphere, lower stratosphere and tropical tropopause layer and assess their transport and chemistry associated with deep convection. Finally, the fast instrument will have a response time sufficient to enable detailed studies of cloud processes affecting the peroxides. With cloud penetrations lasting only a few seconds, current instruments are too slow to resolve clouds, let alone resolve sub-cloud processes.In addition to producing a new in situ measurement capability that significantly enhances the chemistry package for future airborne scientific missions, the project will involve undergraduate students and a post-doctoral scholar in the instrument development, improving their research skill sets in instrument development for atmospheric measurements. The post-doctoral scholar will also gain valuable experience by teaching an undergraduate chemistry class while being mentored by faculty at the U.S. Naval Academy.