Heterogeneous Chemical Processes of Importance in the Stratosphere

拟议的研究包括对大气中涉及云颗粒的重要化学过程的研究。有强烈的迹象表明，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地促进臭氧消耗的形式。该提案中的研究旨在阐明这种过程的机制，并测量化学反应速率等参数，这些参数是模拟极地平流层的行为和预测人造氯氟烃释放的未来影响所必需的。更具体地说，PI计划利用差示扫描量热法等热分析技术以及红外和紫外分光光度法等热分析技术来表征各种与大气有关的冰(由含有不同量的HNO3、H_2SO_4和HCl的水组成)，并通过质谱仪测量各种冰的HCl蒸汽压。PI还计划确定ClONO2和N2O5蒸气与含有适合平流层条件的HCl含量的冰相互作用的反应概率。

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.