Collaborative Research: Ammonia Phase PARtitioning and Transport (APART)

大气中氨（NH3）的排放促进了细颗粒物的形成和氮的沉积，影响人类和生态健康，但对NH3的转化和归宿知之甚少。在这个项目中，研究小组打算对落基山国家公园（RMNP）山麓的主要牛和奶牛饲养场排放的NH3进行空中和地面测量。研究结果将有助于为大气化学家提供信息，并测试一种预测工具，用于预测减少的氮向敏感生态系统的顺风运输。该项目由2个机构和4个pi合作，计划在RMNP山麓进行为期10周的野外活动，以确定(i)大源下风10公里范围内NH3的通量和沉积时间尺度，以及（ii）相同源下风100公里范围内NH3的空间分布和分区。主要的采样平台是怀俄明大学的King Air （UWKA）研究飞机，该飞机配备了新的测量功能，可以增强气体和颗粒的采样策略。气态物质包括还原和氧化氮（NH3和HNO3）、甲烷（CH4）、乙烷（C2H6）、一氧化碳（CO）、二氧化碳（CO2）和水蒸气（H2O），而颗粒物包括气溶胶浓度和大小及其水溶性物质浓度。CH4和C2H6可以跟踪羽流并区分不同的源类型。将飞行数据与从移动监测和现有采样点收集的地面观测数据相结合，为今后更好地解释持续可用的地面数据提供了一种手段。研究结果还将有助于改善交通模型中NH3的代表性，帮助预测当地空气质量并为利益相关者提供信息。两名研究生和几名本科生将在合作的实地活动中获得宝贵的实践经验。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Atmospheric emissions of ammonia (NH3) contribute to the formation of fine particles and nitrogen deposition that affect human and ecological health, yet little is known about NH3 transformation and fate. In this project, the research team intends to perform airborne and ground-based measurements of NH3 emitted from major cattle and dairy feedlots in the foothills of the Rocky Mountain National Park (RMNP). Results will help inform atmospheric chemists and test a forecasting tool for the downwind transport of reduced nitrogen into a sensitive ecosystem. In this collaborative project between 2 institutions and 4 PIs, a 10-week field campaign is planned in the foothills of RMNP to determine (i) fluxes and deposition timescales of NH3 within 10 km downwind of large sources, and (ii) spatial distribution and partitioning of NHx ~100 km downwind of same sources. The main sampling platform is the University of Wyoming King Air (UWKA) research aircraft equipped with new measurement capabilities that allow for enhanced sampling strategies of gases and particulates. Gaseous species include reduced and oxidized nitrogen (NH3 and HNO3), methane (CH4), ethane (C2H6), carbon monoxide (CO), carbon dioxide (CO2) and water vapor (H2O), while particulates include aerosol concentration and size and their water-soluble species concentrations. CH4 and C2H6 allow to track the plume and distinguish between different source types. Integration of flight data with ground-based observations collected from mobile monitoring and existing sampling sites, provides a means to better interpret consistently available ground-based data in the future. Results will also contribute to improved representation of NH3 in transport models, help predict local air quality and inform stakeholders. Two graduate and several undergraduate students will obtain valuable hands-on experiences in a collaborative field campaign.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.