Collaborative Research: Unmanned Aerial Vehicles for Emissions and Chemistry of Volatile Organic Compounds over the Amazon Tropical Forest

该项目将提高对热带森林生态系统大气化学过程的认识。移动剖面系统将用于在不同森林亚型的水平和垂直尺度上表征挥发性有机化合物（VOC）的排放和沉积。这些数据将在旱季和雨季在位于亚马逊中部巴西马瑙斯北郊的Adolfo Ducke森林保护区进行的一系列无人机实验中收集。研究结果将用于改进大气化学模型和数据库，这些模型和数据库描述了植被释放的生物源化合物的特征。本项目将解决的科学问题包括：(1)在100米的中间尺度上，森林景观中挥发性有机化合物排放和沉积的大小和类型的横向异质性是什么？(2)湍流行星边界层中活性VOCs的垂直非均质性和日循环是怎样的？(3)作为挥发性有机化合物（SVOC）氧化光化学反应产物的半挥发性有机化合物（SVOC）的形态和浓度的垂直异质性是什么？横向协议将在中等尺度上描述采样的VOCs的空间变异性，并用于约束和改进MEGAN（自然气体和气溶胶排放模型），这是一个用于模拟生物源排放的框架。垂直协议获得的数据将与混合层反模型技术一起用于估计VOC通量。从这项工作中获得的数据和见解将用于限制和改进目前的大气氧化化学传输模式，并更好地了解亚马逊地区的区域和全球化学传输，特别是与SVOCs和颗粒物质产生的机制以及对未来地球系统变化的敏感性有关的化学传输。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。

This project will improve the understanding of atmospheric chemistry processes over tropical forest ecosystems. A mobile profiling system will be used to characterize emissions and deposition of volatile organic compounds (VOC) over horizontal and vertical scales across different forest sub-types. The data will be collected during a series of drone-enabled experiments conducted in both wet and dry seasons in the Adolfo Ducke Forest Reserve, located on the northern outskirts of Manaus Brazil in central Amazonia. The results will be used to improve atmospheric chemistry modeling and databases that characterize the emissions of biogenic compounds from vegetation.The scientific questions that will be addressed during this project include the following: (1) What is the horizontal heterogeneity in the magnitude and types of VOC emission and deposition for forest landscapes that vary on intermediate scales of 100's m? (2) What is the vertical heterogeneity and diel cycle of reactive VOCs in a turbulent planetary boundary layer? and (3) What is the vertical heterogeneity in the speciation and concentration of semivolatile organic compounds (SVOC) produced as photochemical reaction products of VOC oxidation?The horizontal protocol will characterize the spatial variability of the sampled VOCs at intermediate scale and be used to constrain and improve MEGAN (Model of Emissions of Gases and Aerosols from Nature), a framework used for modeling biogenic emissions. The data obtained by the vertical protocol will be used with the mixed-layer inverse-model technique to estimate VOC fluxes. The data and insights gained from this effort will be used to constrain and improve current chemical transport models of atmospheric oxidation and to provide a better understanding of regional and global chemical transport in Amazonia, especially as related to mechanisms of SVOCs and particulate matter production and susceptibility to future Earth-system changes.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.