VPW: An Investigation of Sea Salt Aerosol Reactions Important to Chlorine Cycling in the Marine Troposphere (Atmospheric Chemistry)

该项目的目标是研究可能从海盐气溶胶中产生气相氯原子的机制--这是大气化学中的一个问题，通过国际和平研究所及其在哈佛的合作者的专业知识的结合，实现了一种独特的方法。将研究四个潜在的重要反应，应用两种不同的实验方法来研究这些表面反应。第一种方法将涉及到研究候选反应，使用可以在相对较高的压力下研究的大表面积/整体表面。理解这些反应及其机理的第二种方法将涉及使用最先进的表面科学光谱技术在低压下研究具有良好特性的单晶表面。尽管后一种方法有其优点，但它尚未被用于研究与大气有关的表面反应。该提案中概述的一系列系统研究旨在确定四个反应中的每一个在从海盐气溶胶中产生气相氯原子方面的作用。这些反应对对流层化学的影响将使用对流层化学的综合理论模型来确定。了解海盐气溶胶产生气相氯原子的机制可以极大地影响我们对对流层化学的理解，以及重要社会决策的基础，如设计污染控制措施和制定安全的氯氟烃替代品(氯氟烃是南极臭氧急剧丧失的原因)。该项目进一步推动了VPW项目的目标，为女性提供通过研究提升她们在科学或工程领域的职业生涯的机会，并通过调查员作为东道主校园榜样的提高知名度，鼓励其他女性在这些领域追求职业生涯。为第二个目标作出贡献的拟议活动包括：为科学和工程专业的研究生和本科生组织和赞助一项辅导方案；组织一次午餐时间研讨会，邀请活跃在科学和工程领域的妇女参加；为本科生开发和提供一系列讲座，讨论化学界当前感兴趣的主题；就年内所取得的研究成果，举办院系研讨会，并在追求研究项目目标的同时，与教职员和学生互动。

This project's goal is to investigate mechanisms which may produce gas phase chlorine atoms from sea salt aerosols--a problem in atmospheric chemistry with a unique approach made possible by the combination of expertise of the PI and her collaborators at Harvard. Four potentially important reactions will be investigated, applying two different experimental approaches to the study of these surface reactions. The first approach will involve studying candidate reactions, using large surface area/bulk surfaces that may be investigated at relatively high pressures. The second approach toward understanding these reactions and their mechanisms will involve studies of well characterized single crystal surfaces at low pressure, using state- of-the-art surface science spectroscopic techniques. Despite its advantages, this latter approach has not been exploited in investigations of surface reactions of atmospheric relevance. A series of systematic studies outlined in the proposal are designed to determine the role of each of four reactions in producing gas phase chlorine atoms from sea salt aerosols. The impact of these reactions on the chemistry of the troposphere will be determined using a comprehensive theoretical model of tropospheric chemistry. Understanding mechanisms which may produce gas phase chlorine atoms from sea salt aerosols could greatly impact our understanding of tropospheric chemistry and the basis for important societal decisions such as the design of pollution controls and formulation of safe alternatives to chlorofluorocarbons (which are responsible for dramatic losses of ozone in the Antarctic). This project furthers VPW program objectives to provide opportunities for women to advance their careers in science or engineering through research, and to encourage other women to pursue careers in these areas through the investigator's enhanced visibility as a role model on the host campus. The proposed activities which contribute to the second objective include: organizing and sponsoring a mentoring program for graduate and undergraduate women in the sciences and engineering; organizing a lunch time symposium featuring women active in science and engineering; developing and delivering a series of lectures geared for undergraduates on topics of current interest to the chemical community; delivering a departmental seminar on the research results obtained during the year; and interacting with faculty and students while pursuing the goals of the research project.