CAREER: Exploring the Physical and Chemical Properties of Light-Absorbing Aerosol: A Single Particle Approach

这一职业项目的重点是研究大气中吸收光线的有机气溶胶粒子的物理和化学性质，特别是那些含有棕色碳(BRC)的粒子。将进行使用单颗粒悬浮的基础实验室研究，以表征这些特性，以便更好地了解和预测BRC气溶胶在环境中的作用。这项研究有望改善对大气BRC气溶胶的描述及其在云、气候、空气质量和健康中的作用。这项工作将表征模型水BRC气溶胶的物理状态、光学性质和化学演化，以更好地了解它们在大气中的演变影响。该提案的目标是：(1)确定特定发色团对BRC颗粒物理状态的贡献；(2)表征与大气相关的代理颗粒中BRC物种的复折射率；以及(3)探索BRC颗粒的光化学老化。线性四极电平衡(LQ-EDB)将用于在受控环境中悬浮含有BRC成分的微米大小的颗粒样品，以模拟大气条件。新的和已建立的工具将用于精确探测悬浮样品的大小、折射率、相形态和组成。样品的物理状态和光学性质将作为相对湿度的函数进行测量，并将探索它们对光解和异质氧化的响应。计划与河滨社区医院的当地住院医生合作，向当地河滨地区的学生群体讲授空气质量的科学和健康影响。该奖项反映了NSF的法定使命，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 CAREER project is focused on the study of the physical and chemical properties of light-absorbing organic aerosol particles in the atmosphere, especially those containing brown carbon (BrC). Fundamental laboratory studies using single particle levitation will be performed to characterize these properties to better understand and predict the role of BrC aerosol in the environment. This research is expected to lead to an improved description of atmospheric BrC aerosol and their role in clouds, climate, air quality and health.This effort will characterize the physical state, optical properties, and chemical evolution of model aqueous BrC aerosol to better understand their evolving impacts in the atmosphere. The goals of the proposal are to: (1) Identify the contributions of specific chromophores to the physical state of BrC particles; (2) Characterize the complex refractive index of BrC species in atmospherically relevant proxy particles; and (3) Explore the photochemical aging of BrC particles. A linear quadrupole electrodynamic balance (LQ-EDB) will be used to levitate micrometer-sized particle samples containing BrC constituents in a controlled environment to mimic atmospheric conditions. New and established tools will be applied to precisely probe the size, refractive index, phase morphology, and composition of suspended samples. The physical state and optical properties of the samples will be measured as a function of relative humidity and their response to photolysis and heterogeneous oxidation will be explored.A partnership is planned with local resident doctors at Riverside Community Hospital to provide an opportunity to teach the science and health impacts of air quality to populations of students in the local Riverside area.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.