Detection of Inorganic Dihalogen Gases (Cl2, Br2, I2, BrCl, and ICl) in the Marine Atmosphere

该奖项支持对沿海和海洋空气中的几种二卤化合物Cl2（分子氯）、Br2（分子溴）、I2（分子碘）、BrCl（氯化溴）和ICl（氯化碘）进行现场测量。测量将使用负离子谱中的大气压化学电离串联质谱（APCI/MS/MS）进行。实验室测试和沿海环境空气中Cl2和I2的初步现场测量表明，该技术能够实现低pptv检测限。该项目的目标是：(1)验证和进一步发展空气中重卤素的分析方法，(2)探索这些气体在沿海和偏远海洋空气中的分布，(3)测试关于海洋空气中卤素化学的起源和影响的各种假设。计划在马里布、加利福尼亚州、斯克里普斯码头和百慕大进行实地测量。这项研究很重要，因为卤素化合物在平流层化学中起着至关重要的作用，而且在对流层中，它们可以释放卤素原子，破坏臭氧，充当氧化剂，影响不饱和碳氢化合物的寿命，并改变还原硫气体的反应途径。迄今为止，对海洋对流层中这些活性卤素化合物的直接测量很少。该项目将支持一名研究生和本科生。它还将有助于培训一名地球科学高中教师。

This award supports field measurements of several dihalogen compounds, Cl2 (molecular chlorine), Br2 (molecular bromine), I2 (molecular iodine), BrCl (bromine chloride), and ICl (iodine chloride) in coastal and marine air. The measurements will be made using atmospheric pressure chemical ionization tandem mass spectrometry (APCI/MS/MS) in the negative ion spectrum. Laboratory tests and preliminary field measurements of Cl2 and I2 in ambient coastal air indicate that this technique is capable of low pptv detection limits. The goals of this project are (1) to validate and further develop the analytical method for dihalogens in air, (2) to explore the distribution of these gases in coastal and remote marine air, and (3) to test various hypotheses regarding the origin and impact of halogen chemistry in marine air. Field measurements are planned for Malibu, CA, the Scripps pier, and Bermuda. This research is important because halogen compounds play a critical role in stratospheric chemistry, but also in the troposphere, where they can release halogen atoms that can destroy ozone and act as oxidants and affect the lifetimes of unsaturated hydrocarbons and alter reaction pathways for reduced sulfur gases. To date, there are few direct measurements of these reactive halogen compounds in the marine troposphere. This project will support a graduate student as well as undergraduate students. It will also contribute to the training of an Earth Sciences high school teacher.