Identification of the Chemical Mechanisms of Heterogeneous Processes on Sea Salt Particles Using Stable Chlorine Isotope Ratios

ATM-9529451瓦伦，加州大学马丁分校，圣地亚哥标题：用稳定的氯同位素比值鉴定海盐颗粒非均相过程的化学机理现场和实验室证据表明，大量的海盐氯化物是通过一个或多个化学途径挥发的，而不是在与硝酸或硫酸反应后解吸盐酸。实验室实验表明，氯化钠与氮氧化物和臭氧等大气活性物质之间可以发生非均相反应，但这些反应在对流层低层的普遍程度仍不清楚。该项目的主要目标是使用稳定的氯同位素比率来支持或消除可能导致整个世界海洋中氯挥发的反应。在形成或断裂共价键的化学反应过程中，同位素比率会发生变化。因此，不同的化学反应导致不同的同位素特征。测得的残留盐颗粒中的同位素分馏可以与实验室模拟的反应的分馏系数进行比较。在这个项目中，将与芝加哥大学的乔纳森·阿巴特教授合作进行实验室调查，以确定单个挥发反应的同位素分馏系数。此外，将对来自不同海洋区域的存档气溶胶样本进行氯分馏分析，根据这些信息，将确定导致气溶胶中氯挥发的不同过程。

Abstract ATM-9529451 Wahlen, Martin University of California, San Diego Title: Identification of the Chemical Mechanisms of Heterogeneous Processes on Sea Salt Particles Using Stable Chlorine Isotope Ratios Field and laboratory and laboratory evidence indicates that significant quantities of sea salt chloride are volatilized by one or more chemical pathways other than desorption of hydrochloric acid following reaction with nitric or sulfuric acid. Laboratory experiments indicate that heterogeneous reactions can occur between sodium chloride and reactive atmospheric species such as nitrogen oxides and ozone, however, the prevalence of these reactions in the lower troposphere is still not understood. The primary objective of this project is to use stable chlorine isotopes ratios to support or dismiss reactions potentially responsible for chlorine volatilization throughout the world's oceans. The isotopic ratios are altered during chemical reactions where covalent bonds are formed or broken. Thus, different chemical reactions lead to different isotopic signatures. Measured isotopic fractionation in residual salt particles can be compared to the fractionation factors of the reactions simulated in the laboratory. In this project, laboratory investigations will be carried out in collaboration with Prof. Jonathan Abbatt at the University of Chicago to determine the isotopic fractionation factors of individual volatilization reactions. In addition, archived aeroslo samples from various oceanic regions will be analyzed for chlorine fractionation, From this information, the heterogeneous processes responsible for chlorine volatilization in the aerosols will be determined.