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

该项目将开发一种使用同位素稀释的化学电离质谱仪(CIMS)系统，用于以10赫兹的时间分辨率原位测定大气中的过氧化氢。该仪器将被认证用于包括NSF湾流-V(GV)在内的研究飞机。它将提供一种新的工具来解决围绕过氧化物大气化学的一些悬而未决的科学问题。该仪器的快速响应还将使我们能够研究对流层中的过氧化氢通量，大大提高我们对大陆和海洋边界层中过氧化氢沉积和奇数氢损失的理解。利用GV平台，该仪器将有助于量化过氧化氢和甲基过氧化氢在对流层上部、平流层下部和热带对流层顶层的分布，并评估它们与深对流有关的输送和化学作用。最后，FAST仪器将有足够的响应时间来详细研究影响过氧化物云的过程。由于云层穿透只持续几秒钟，目前的仪器分解云层太慢，更不用说解析亚云过程了。除了生产一种新的现场测量能力，显著增强未来空中科学任务的化学包外，该项目还将让本科生和一名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。这位博士后学者还将在美国海军学院的教员指导下教授本科生化学课程，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.