Atmospheric Interfacial Chemistry

1.本研究的目的是在理解非均相化学的基础上，研究气候变化和大气化学。非均相化学在大气中痕量物种的循环中起着重要作用。该研究项目由4名独立研究人员(日本2名，美国1名，瑞士1名)组织，他们之间非常积极地交流有关的科学知识。主要研究对象是在气溶胶和海盐颗粒上进行的非均相化学反应。(1)Koda教授(与气液界面相关的传质和非均相反应)发展了撞击流技术，测量了NOx_2·OH和I_2在水表面的吸收系数。(2)Akimoto教授(海盐上活性卤素物种的产生及其与臭氧破坏的关系)研究了涉及碱性卤化物粒子和气态臭氧的非均相反应，并试图探索海盐粒子作为对流层活性卤素物种来源的可能作用。(3)Molina教授(与极地平流层云有关的非均相化学)研究了冰粒形成的物理化学特征，讨论了卤素和氮氧化物物种对极地平流层云的反应。(4)Rossi博士(多相反应动力学和大气环境化学)利用Knudsen格子方法研究了亚硝酸和氯化氢在固体表面的非均相反应。通过调查人员的相互访问，国际合作取得了进展。例如：科达访问莫利里亚(1997年6月)，罗西访问科达(1997年11月)。

1. The objective of the present research is to study the climate change and atmospheric chemistry on the basis of the understanding of heterogeneous chemistry, which plays an important role in the circulation of trace species in the atmosphere. This research project is organized by 4 independent researchers (two from Japan, one from USA, and one from Switzerland) who exchange the scientific knowledge concerned among them very actively. The main research target is the heterogeneous chemical reactions which proceed on aerosols and sea salt particles.2. (1) Prof.Koda (Mass transport and heterogeneous reactions related to gas-liquid interfaces) has developed the novel impinging flow technique, and measured the uptake coefficients of Nox_2 OH and I_2 to the aqueous surfaces. (2) Prof.Akimoto (Production of active halogen species on sea salts and its relation to ozone destruction) has investigated heterogenous reactions involving alkali halide particles and gaseous ozone and tried to explore the possible role of sea salt particles as a source of reactive halogen species on the troposphere. (3) Prof. Molina (Heterogenous chemistry related to polar stratospheric clouds) has studied the physico-chemical characteristics of ice particles formation and discussed the reactions of halogen and nitrogen oxides species on polar stratospheric clouds. (4) Dr.Rossi (Kinetics of heterogeneous reactions and atmospheric environmental chemistry) investigated the heterogeneous reactions such as those between nitrous acid and hydrogen chloride on solid surfaces by means of Knudsen cell method.3. The international collaboration has progressed through the mutual visit among the investigators. Some examples are : visit of Koda to Moliria (June, 1997), visit of Rossi to Koda (Nov., 1997).