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，Cl 2（分子氯），Br 2（分子溴），I2（分子碘），BrCl（氯化溴）和ICl（氯化碘）进行现场测量。将使用大气压化学电离串联质谱法（APCI/MS/MS）在负离子光谱中进行测量。实验室测试和初步的现场测量的Cl 2和I2在沿海环境空气中表明，这种技术是能够低pptv检测限。该项目的目标是（1）验证和进一步开发空气中二卤的分析方法，（2）探索这些气体在沿海和偏远海洋空气中的分布，以及（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。计划在加利福尼亚州的马里布、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关键作用，但在对流层中也起着关键作用，它们可以释放卤素原子，这些卤素原子可以破坏臭氧并作为氧化剂，影响不饱和烃的寿命，并改变还原硫气体的反应途径。迄今为止，很少有直接测量这些反应性卤素化合物在海洋对流层。这个项目将支持研究生以及本科生。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.