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

该项目将开发一个化学电离质谱系统，利用同位素稀释法，以10赫兹的时间分辨率就地测定大气中的过氧化物。该仪器将被认证用于研究飞机，包括NSF湾流-V（GV）。它将提供一个新的工具，以解决一些悬而未决的科学问题周围的大气化学的过氧化物。该仪器的快速响应还将使对流层中过氧化物的通量研究成为可能，大大提高我们对大陆和海洋边界层中氢过氧化物沉积和奇氢损失的理解。利用GV平台，该仪器将有助于量化对流层上部、平流层下部和热带对流层顶层中过氧化氢和甲基氢过氧化物的分布，并评估其与深对流有关的输送和化学性质。最后，快速仪器的响应时间将足以对影响过氧化物的云过程进行详细研究。由于云层穿透仅持续几秒钟，目前的仪器太慢，无法分辨云层，更不用说分辨云下过程了。除了产生一种新的原位测量能力，大大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师指导下教授本科化学课，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.