Collaborative Research: Airborne Hydrogen Peroxide and Methylhydroperoxide Measurements during the Deep Convective Clouds and Chemistry (DC3) Experiment

在2012年5月至6月的深对流云和化学（DC 3）实地活动期间，将使用NSF/NCAR湾流V研究飞机上的新化学电离质谱仪（CIMS）测量过氧化氢和甲基氢过氧化物。两种过氧化物的测量将在10 Hz下进行，允许水平和垂直样品分辨率分别为20米和2米。在入口处连续添加同位素标记的标准气体，以在压力、温度、水蒸气和其他环境变量的所有变化下为两种物质提供一致校准。将使用地面湿化学校准系统进行广泛的任务前、综合、试飞和部署评估和比较。DC 3空中过氧化物观测将提供：1）这些物质在孤立的深对流云中及其周围的分布，2）对流层上部和平流层下部奇氢化学的约束数据，3）限制中纬度大陆云垂直输送奇氢前体的数据，4）限制云滴和水凝物清除可溶性物质的数据，5）在有和没有闪电增加的氮氧化物的情况下对流层上部对流气团化学老化的探测器，以及6）在云底温度、垂直速度、冻结水平和冰川作用以及闪电等云暴特性方面表征主题1-5的方差。结果将是显着的对流层氧化剂和臭氧化学和它们的区域到全球的分布;在寒冷，低比湿，混合阳光条件下的非均质气体气溶胶化学;气溶胶化学演变和它们的区域到全球的分布;并最终空气质量和气候。该仪器系统是新颖的，代表了机载过氧化氢仪器的重大进步。一名博士后、一名研究生和一名或多名本科生将参与实验。数据将在国家大气研究中心存档，结果将发表在同行评审的期刊上。

Measurements of hydrogen peroxide and methylhydroperoxide will be made using a new chemical ionization mass spectrometry (CIMS) instrument on board the NSF/NCAR Gulfstream V research aircraft during the Deep Convective Clouds and Chemistry (DC3) field campaign in May-June 2012. Measurements of the two peroxides will be made at 10 Hz allowing horizontal and vertical sample resolution on the order of 20 meters and 2 meters, respectively. Through-the-inlet isotopically-labeled standard gas additions will be made continuously to provide coincident calibration for both species under all encountered variations in pressure, temperature, water vapor and other environmental variables. Extensive pre-mission, integration, test fight, and deployment evaluations and comparisons will be made using a ground-based wet-chemical calibration system.The DC3 airborne peroxide observations will provide: 1) distributions of these species in and around isolated deep convective clouds, 2) constraining data on odd-hydrogen chemistry in the upper troposphere and lower stratosphere, 3) constraining data on vertical transport of odd-hydrogen precursors by deep mid-latitude continental clouds, 4) constraining data on the scavenging of soluble species by cloud droplets and hydrometeors, 5) a probe of convected air-mass chemical aging in the upper troposphere with and without lightning-added nitrogen oxides, and 6) characterization of the variance of topics 1-5 across cloud-storm properties such as cloud base temperature, vertical velocity, freezing level and glaciation, and lightning. Results will be significant to tropospheric oxidant and ozone chemistry and their regional-to-global distributions; to heterogeneous gas-aerosol chemistry under cold, low specific humidity, and mixed sunlight conditions; to aerosol chemical evolution and their regional-to-global distributions; and ultimately to air quality and climate. The instrument system is novel and represents a significant advance in airborne peroxide instrumentation. One post-doctoral fellow, one graduate student and one or more undergraduate students will participate in the experiment. Data will be archived at the National Center for Atmospheric Research and results published in peer-reviewed journals.