EAGER: Exploring the Ground-Level and Elevated Sources of New Particle Formation Using Aerosol Size- and Hygroscopicity-Resolved Turbulent Flux Measurement Technique

这个急切的项目是对评估大气中新粒子形成事件的一种新方法进行评估的一项“概念验证”工作。已经开发出一种方法，通过测量尺寸分辨的颗粒的垂直通量及其吸水能力来区分地面和高空的超细颗粒来源。了解新粒子的形成对于估计城市地区地面颗粒物浓度和设计有效的空气质量控制策略至关重要。本研究的目的是评估：(1)测量涡旋协方差和大小选择和吸湿性分辨的松弛涡旋积累(Hy-res REA)粒子垂直通量是否可以用于分离新粒子形成的地面和高空来源；以及(2)残留层新粒子形成事件可以明确地与在地表检测到的B类成核事件(在B类事件期间，检测到的最小粒子直径大于约10 nm)联系在一起。在2020年5月，能源部位于俄克拉荷马州的南部大平原(SGP)站点将对一天中4个不同时间段的尺寸和吸湿性解析的垂直湍流气溶胶通量进行测量，那里有丰富的辅助数据，包括每日边界层动态的长期统计数据以及气溶胶数量和吸湿性的每日轮廓。该奖项反映了NSF的法定任务，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This EAGER project is a "proof of concept" effort to evaluate a new method for assessing new particle formation events in the atmosphere. A method has been developed to distinguish between ground-based and elevated sources of ultrafine particles by measuring the vertical fluxes of size-resolved particles and their ability to absorb water. Understanding new particle formation is critical to estimating ground level particle concentrations and designing effective air quality control strategies in urban areas.The objectives of the study are to evaluate if: (1) measurements of eddy covariance and size-selected and hygroscopicity-resolved relaxed eddy accumulation (Hy-RES REA) vertical fluxes of particles can be used to separate ground-level and elevated sources of new particle formation; and (2) residual layer new particle formation events can be unambiguously linked to observed Class B nucleation events (during Class B events the smallest detected particle diameters are larger than about 10 nm in size) detected at the surface. During May of 2020, measurements will be made of size- and hygroscopicity-resolved vertical turbulent aerosol fluxes during 4 different time periods over the day at the Department of Energy's Southern Great Plains (SGP) site in Oklahoma, where a wealth of ancillary data are available, including long-term statistics of the diurnal boundary layer dynamics and diurnal profiles of aerosol number and hygroscopicity.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.