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

本CAREER项目的重点是研究大气中光吸收有机气溶胶颗粒的物理和化学性质，特别是那些含有棕色碳（BrC）的颗粒。基础实验室研究使用单粒子悬浮将进行这些特性的特点，以更好地了解和预测的BrC气溶胶在环境中的作用。这项研究有望改善对大气中溴化碳气溶胶及其在云、气候、空气质量和健康中的作用的描述，并将描述模型含水溴化碳气溶胶的物理状态、光学特性和化学演变，以更好地了解其在大气中不断演变的影响。该提案的目标是：（1）确定特定发色团对溴化碳粒子物理状态的贡献;（2）确定与大气相关的代用粒子中溴化碳物种的复折射率;（3）探索溴化碳粒子的光化学老化。将使用线性四极电动天平（LQ-EDB）在受控环境中悬浮含有BrC成分的微米级颗粒样品，以模拟大气条件。新的和建立的工具将被应用于精确探测悬浮样品的大小，折射率，相形态和组成。将测量样品的物理状态和光学性质作为相对湿度的函数，并探索它们对光解和非均相氧化的响应。计划与滨江社区医院的当地住院医生建立伙伴关系，为当地滨江地区的学生提供科学和健康影响的教育机会。该奖项反映了NSF的法定使命，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 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.