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.
