An Investigation of Halogen Activation in the Lower Stratosphere and Upper Troposphere

该项目支持通过气球平台测量平流层下层的卤素氧化物（ClO和BrO）。每年将有四个气球在怀俄明州的拉勒米附近发射。一种新的轻型仪器将与光散射仪器（由Deshler教授建造，U. Wyoming）一起部署，用于测量大气气溶胶的粒径分布和数量密度。臭氧也将使用电化学电池进行测量。每年将增加一次二氧化碳和粒子质量及组成的测量。这项工作的目的是表征卤素氧化物的季节变化，这些卤素氧化物对太阳光照、温度、微量气体分布和气溶胶浓度的变化做出反应，并解决以下突出问题：(1)今天平流层低层ClO和BrO的丰度在季节和年际上有多大的变化？(2)这种变率有多少可归因于非均相化学和气溶胶表面积的变化？(3)粒径、表面积和温度对非均相化学和卤素活化的相对贡献是什么？(5)卷云是否激活平流层下层和对流层上层的氯？

This project supports measurements of halogen oxides (ClO and BrO) in the lower stratosphere from balloon platforms. Four balloons per year will be launched near Laramie, WY. A new lightweight instrument will be deployed together with light scattering instruments (built by Prof. Deshler, U. Wyoming) that measure particle size distributions and number densities of atmospheric aerosols. Ozone will be also measured using electrochemical cells. Once per year, measurements of carbon dioxide and particle mass and composition will be added. The objectives of this work are to characterize the seasonal variability of the halogen oxides, species that respond to changes in solar illumination, temperature, trace gas distributions, and aerosol concentrations, and address the following outstanding issues: (1) How variable, seasonally and interannually, are abundances of ClO and BrO in the lower stratosphere today? (2) How much of this variability can be attributed to heterogeneous chemistry and to changes in aerosol surface area? (3) What are the relative contributions of particle size, surface area, and temperature to heterogeneous chemistry and halogen activation? (5) Do cirrus clouds activate chlorine in the lower stratosphere and upper troposphere?