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

该项目支持从气球平台测量平流层下部的卤素氧化物(ClO和BrO)。每年将在怀俄明州拉勒米附近发射四个气球。一种新的轻型仪器将与光散射仪器(由怀俄明州大学的Deshler教授建造)一起部署，用于测量大气气溶胶的颗粒尺寸分布和数密度。臭氧也将使用电化学池进行测量。每年一次，将增加二氧化碳和颗粒物质量和组成的测量。这项工作的目的是描述卤素氧化物的季节变化，即对太阳光照、温度、痕量气体分布和气溶胶浓度变化做出反应的物种，并解决以下突出问题：(1)今天平流层低层中ClO和BrO的丰度在季节和年际上有多大变化？(2)这种变化在多大程度上可以归因于非均质化学和气溶胶表面积的变化？(3)颗粒大小、表面积和温度对非均质化学和卤素激活有何相对贡献？(5)卷云是否激活了平流层低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?