Collaborative Research: Laboratory and Theoretical Studies of Mineral Aerosol Heterogeneous Interactions with Mixtures of Atmospheric Gases at Relevant Temperatures and Humidities

合作研究：相关温度和湿度下矿物气溶胶与大气气体混合物异质相互作用的实验室和理论研究

• 批准号: 0927944
• 负责人: David Cwiertny
• 金额: $ 5.22万
• 依托单位: University of Iowa
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0927944&HistoricalAwards=false
• 关键词: Collaborative; Research; Laboratory; Theoretical; Studies

The objective of this project is to determine the heterogeneous reactivity of natural mineral aerosol components, representative of chemically-processed and freshly-emitted mineral aerosol, with single atmospheric gases and with gaseous mixtures over atmospherically relevant temperature and humidity ranges. A low-pressure, low-temperature Diffuse Reflectance Infrared Fourier Transform Spectrometer (DRIFTS) equipped reaction chamber will be used to carry out laboratory studies. The chamber system allows for in situ, simultaneous gas- and condensed-phase measurements of the heterogeneous uptake of reactive gases and gaseous mixtures on thin films of mineral components representative of those observed in the atmosphere. Heterogeneous uptake will be studied experimentally as a function of temperature, relative humidity and reactive gas concentration. Associated theoretical studies will (a) complement experiments by interpreting infrared spectra and identifying intermediate and terminal adsorbed reaction products, providing additional mechanistic detail, (b) model electronic properties of the mineral dust components studied and determine the effects of metal impurities on surface reactivity, and (c) determine how heterogeneous reactions on mineral dust surfaces alter these electronic properties.Results of the studies will provide important mechanistic, kinetic and thermodynamic details needed for incorporation into current atmospheric chemistry models in order to more accurately model the effects of heterogeneous reactivity (impacts on tropospheric chemistry), surface composition (impacts on health, climate and further reactivity) and water adsorption (impacts on visibility and climate) in the Earth's atmosphere. The work will extend beyond previous studies of mineral dust aerosol heterogeneous chemistry that were limited to heterogeneous uptake under dry conditions, room temperature and in the presence of only a single reactive gas. The project will foster a unique partnership between a large university and a small liberal arts college. This relationship will cultivate experiential learning via active educational research opportunities for undergraduate students and aid in the recruitment of well-trained, science-oriented students at the undergraduate and graduate levels. Beyond traditional dissemination, research results will be incorporated into undergraduate teaching curricula at Hendrix College. Additionally, hands-on workshops and laboratory experiments will be conducted at Hendrix College using the DRIFTS system.

该项目的目的是确定天然矿物质气溶胶成分的异质反应性，代表了化学加工和新鲜发射的矿物气溶胶，具有单一大气气体，并具有在大气中相关的温度和湿度范围内的气态混合物。低压的低温弥散反射率红外傅立叶变换光谱仪（漂移）的反应室将用于进行实验室研究。腔室系统允许原位，同时对反应性气体的异质吸收的气体和冷凝相测量，以及代表大气中观察到的矿物质成分的薄膜上的气态混合物。将根据温度，相对湿度和反应性气体浓度来实验研究异质摄取。相关的理论研究将（a）通过解释红外光谱并识别中间和末端吸附的反应产物来进行补体实验，提供其他机械细节，（（b）模型的矿物灰尘组件的电子性能并确定金属杂质对表面反应性的影响，并确定对矿物质的污染物的影响，这些尘埃对矿物质的范围进行了研究。在当前的大气化学模型中掺入所需的动力学和热力学细节，以更准确地模拟异质反应性（对对流层化学的影响），表面组成（对健康，气候和进一步反应性的影响）和水的吸附（对地球大气中的可见度和气候的影响）。这项工作将超越先前对矿物粉尘气溶胶异质化学的研究，这些化学仅限于在干燥条件，室温和仅存在单个反应性气体的情况下进行异质摄取。该项目将建立大型大学和小型文科学院之间的独特伙伴关系。这种关系将通过为本科生的积极教育研究机会培养体验式学习，并帮助招募本科和研究生级别的训练有素的，以科学为导向的学生。除传统传播外，研究结果还将纳入亨德里克斯学院的本科教学课程中。此外，将使用漂移系统在Hendrix College进行动手研讨会和实验室实验。