报告题目：Are unregulated very short-lived substances important for stratospheric ozone depletion?
报 告 人：Ryan Hossaini 教授
报告时间：2025年9月18日（周四）下午15：00
线上腾讯会议：622-338-800（密码：127261）
主 持 人：侯雪伟 副教授
报告人简介：
Ryan Hossaini是英国兰卡斯特大学的大气化学教授。他主要利用全球模型研究地球大气化学成分的变化及长期演变，并探讨其对气候、臭氧层和空气质量的影响。作为国际臭氧委员会的当选成员，他参与撰写了多份世界气象组织/联合国环境规划署（WMO/UNEP）《臭氧消耗科学评估报告》。目前，他正主持国际APARC模式比对项目VSLS-MIP1，并担任英国皇家气象学会大气化学组（ACSG）的联合主席。
报告简介：
Halogenated Very Short-Lived Substances (VSLS) represent a growing source of ozone-depleting chlorine in the stratosphere. Unlike long-lived ozone-depleting gases (e.g. CFCs, HCFCs), the production and use of VSLS is not controlled by the UN Montreal Protocol. Global measurements at the surface and in the upper troposphere show the atmospheric abundance of several species (e.g. dichloromethane) have increased substantially since the early 2000s. In this talk, I will present a bottom-up assessment of five prominent industrially-emitted VSLS: dichloromethane (CH2Cl2), perchloroethylene (C2Cl4), chloroform (CHCl3), trichloroethylene (C2HCl3) and 1,2-dichloroethane (CH2ClCH2Cl). The analysis covers a 21-year period (2002 to 2022) and considers fugitive emissions from VSLS production and use as chemical feedstocks and releases from emissive applications (e.g. solvent use). The analysis shows that VSLS emissions are especially large in South and East Asia. Using the new emissions, I will present chemical transport model simulations that quantify how much chlorine from VSLS enters the stratosphere, including via the Asian Summer Monsoon system. The significance of growing VSLS emissions for stratospheric composition and relevant policy are discussed.
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大气物理学院
2025年9月15日
