Determination of Heterogeneous Photochemistry Related to Atmospheric Reactive Nitrogen Species

氮氧化物（NOx = NO+NO2）在地面臭氧形成、平流层臭氧消耗和酸沉积中起着关键作用。了解活性氮（NOY，其中NOY定义为NOx和NOx的大气氧化产物的总和）的大气化学对污染防治工作至关重要。虽然大量NOY的均相气相光化学已经被研究过，但对NOY的非均相光化学，如硝酸（HNO3）和过氧硝酸（HO2NO2）的了解甚少。在低nox环境中，地面表面吸附的HNO3的光解作用被认为是白天HONO的主要来源。特别是对HNO3/H2O共沉积在表面的紫外吸收截面和光解量子产率知之甚少。该项目旨在表征在没有和有水蒸气的情况下，表面吸附的HNO3， HNO3/H2O共同沉积在表面，以及表面吸附的HO2NO2的异质光解作用。表面吸附的HNO3、HNO3/H2O和HO2NO2的波长相关紫外吸收截面将使用布鲁斯特角腔衰落光谱测定。将激光光解与布鲁斯特角腔衰荡光谱（熔融硅表面）或腔衰荡光谱（铝或冰膜表面）相结合，测量这些物质的光解途径和非均相光解的产物产量。该项目将为评估非均相光解作用在将氮氧化物储层转化为活性形式和产生对流层奇数氢自由基方面的作用提供必要的信息。该项目将直接导致一名研究生和一名博士后的研究培训。除了由项目主任、博士后和研究生在国内和国际会议上展示研究成果，并在专业期刊上发表研究成果外，项目主任朱磊博士还计划定期在该地区的当地高校举办讲座，与该地区的科学家分享研究成果，激发学生对科学的兴趣，促进不同机构之间的智力交流。首席研究员（PI）还致力于增加外展工作，并为大学教育的多样性和包容性目标做出贡献。纽约州立大学奥尔巴尼分校现有的外展项目，如牧羊人项目。牧羊人项目的目标是与历史上少数民族大学的教师建立长期合作关系。PI计划成为纽约州立大学奥尔巴尼分校牧羊人项目的积极成员。

Nitrogen oxides (NOx = NO+NO2) play a pivotal role in ground-level ozone formation, stratospheric ozone depletion, and acid deposition. Understanding atmospheric chemistry of reactive nitrogen species (NOY, where NOY is defined as the sum of NOx and the atmospheric oxidation products of NOx) is critical to pollution prevention and control efforts. While the homogeneous gas phase photochemistry of a large number of NOY has been studied, much less is known about the heterogeneous photochemistry of NOY species such as nitric acid (HNO3) and peroxynitric acid (HO2NO2). The photolysis of adsorbed HNO3 on ground surfaces has been proposed as a major daytime source of HONO in low-NOx environments. Little is known in particular about the UV absorption cross sections and the photolysis quantum yields of HNO3/H2O co-deposited on surface. The project seeks to characterize heterogeneous photolysis of surface-adsorbed HNO3 both in the absence and in the presence of water vapor, of HNO3/H2O co-deposited on surface, and of surface-adsorbed HO2NO2. Wavelength-dependent UV absorption cross sections of surface-adsorbed HNO3, HNO3/H2O, and HO2NO2 will be determined using Brewster-angle cavity ring-down spectroscopy. The photodissociation pathways and product yields from the heterogeneous photolysis of these species will be measured by combining laser photolysis either with Brewster angle cavity ring-down spectroscopy (fused silica surface) or with cavity ring-down spectroscopy (Al or ice film surface). The project will provide information essential to the assessment of the role of heterogeneous photolysis in converting NOx reservoirs into active forms and in producing tropospheric odd hydrogen radicals.The project will directly lead to the research training of a graduate student and a postdoctoral scholar. In addition to presenting research findings at national and international conferences by the project director, postdoctoral scholar and graduate student, and publishing results in professional journals, the project director, Dr. Lei Zhu, plans to periodically give lectures in the local colleges and universities in the region to share the research results with scientists in the area, excite students' interests in science, and promote intellectual exchanges between different institutions. The Principal Investigator (PI) also plants to increase outreach efforts and to contribute to the goal of diversity and inclusiveness in university education. SUNY-Albany has existing outreach programs such as the Shepherd Project. The Shepherd Project has the goal of establishing long-term partnerships with faculty at historically minority colleges. The PI plans to become an active member in the Shepherd Program at SUNY-Albany.