Photochemistry of solutes in/on water ice

美国国家科学基金会化学部的环境化学科学项目支持加州大学戴维斯分校的科特·阿纳斯塔西奥教授研究雪中的光化学反应如何显著影响雪的化学和组成以及上面的大气。我们对这些过程的速率或机制知之甚少，而且更复杂的是，给定溶质的光化学似乎取决于溶质在冰中/冰上的位置。这项建议的两个主要目标是：(1)量化与环境有关的溶质的光反应速率如何随冰中/冰上的位置变化；(2)确定冰点下降模型是否可以预测溶质的反应性。这些目标将通过仔细描述冰样和光照条件的实验室实验来实现。这项工作有可能改变我们对冰中/冰上分子反应的理解，因为它揭示了化学如何随着冰舱的变化而变化，并提供了一个可用于模拟雪化学的实验确认的动力学框架。这项工作的广泛影响包括：(1)培训和指导一名博士后研究员、一名研究生和几名本科生；(2)将研究成果整合到本科生和研究生课程中；(3)在萨克拉门托举办一系列关于气候变化的研讨会，让州、县和市的政策制定者以及公众参与进来。

The Environmental Chemical Sciences Program in the Chemistry Division at the National Science Foundation supports Professor Cort Anastasio of the University of California- Davis to study how photochemical reactions in snow can significantly affect the chemistry and composition of snow and the overlying atmosphere. We know relatively little about the rates or mechanisms of these processes, and further complicating matters, it appears that the photochemistry of a given solute depends on where the solute is located in/on ice. The two main goals of this proposal are to: (1) quantify how the photoreaction rates of environmentally relevant solutes vary with location in/on ice and (2) determine whether a freezing point depression model can predict solute reactivity. These goals will be achieved using laboratory experiments with carefully characterized ice samples and illumination conditions. This work has the potential to transform our understanding of molecular reactions in/on ice by revealing how chemistry varies with ice compartment and by providing an experimentally-confirmed kinetic framework that could be used to model snow chemistry. The broader impacts of this work include: (1) training and mentoring a postdoctoral fellow, a graduate student, and several undergraduate students, (2) integrating research results into undergraduate and graduate courses, and (3) developing a seminar series on climate change to be offered in Sacramento to engage state, county, and city policy makers as well as the public.