Heterogeneous Chemical Processes of Importance in the Stratosphere

平流层中重要的非均相化学过程

• 批准号: 9017150
• 负责人: Mario Molina
• 金额: --
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-01-15 至 1994-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9017150&HistoricalAwards=false
• 关键词: Heterogeneous; Chemical; Processes; Importance; Stratosphere

The proposed research consists of studies of chemical processes of importance in the atmosphere which involve cloud particles. There are strong indications that polar stratospheric clouds are chemically very active, transforming stable chlorine compounds to a form that efficiently promotes ozone depletion. The studies in this proposal are aimed at elucidating the mechanism for such processes, and at measuring parameters such as chemical reaction rates, which are needed to model the behavior of the polar stratosphere and to predict future effects of the release of man-made chlorofluorocarbons. More specifically, the PI plans to characterize the various ices of atmospheric interest (which consist of water with varying amounts of HNO3, H2SO4 and HCl) by means of thermal analysis techniques such as differential scanning calorimetry, and by infrared and ultraviolet spectrophotometry and to measure the vapor pressures of HCl for the various ices as a function of the ice composition via mass spectrometry. The PI also plans to determine reaction probabilities for ClONO2 and N2O5 vapors interacting with ices containing amounts of HCl which are appropriate for stratospheric conditions.

拟议的研究包括对大气中涉及云粒子的重要化学过程的研究。有强有力的迹象表明，极地平流层云在化学上非常活跃，将稳定的氯化合物转化为一种有效促进臭氧消耗的形式。本提案中的研究旨在阐明这些过程的机制，并测量化学反应速率等参数，这些参数是模拟极地平流层行为和预测人造氟氯化碳排放的未来影响所必需的。更具体地说，PI计划通过热分析技术（如差示扫描量热法）来表征各种大气感兴趣的冰（由含有不同数量的HNO3、H2SO4和HCl的水组成），通过红外和紫外分光光度法，并通过质谱法测量各种冰中HCl的蒸气压作为冰成分的函数。PI还计划确定ClONO2和N2O5蒸气与含有适量HCl的冰相互作用的反应概率，这适用于平流层条件。