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Cort Anastasio教授研究雪中的光化学反应如何显著影响雪和上覆大气的化学和成分。相对而言，我们对这些过程的速率和机理所知甚少，更复杂的是，已知溶质的光化学反应似乎取决于溶质在冰上的位置。本提案的两个主要目标是：(1)量化与环境相关的溶质的光反应速率如何随冰内/冰上位置的变化而变化；(2)确定冰点降低模型是否可以预测溶质的反应性。这些目标将通过具有仔细表征的冰样品和照明条件的实验室实验来实现。这项工作有可能改变我们对冰内/冰上分子反应的理解，揭示化学如何随冰室而变化，并提供一个实验证实的动力学框架，可用于模拟雪化学。这项工作的广泛影响包括：(1)培训和指导一名博士后、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气候变化研讨会，吸引州、县、市的决策者以及公众。

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.