CAREER: Origin and Evolution of the Light Absorption of Biomass Burning Aerosol

这个CAREER项目的重点是研究生物质燃烧气溶胶吸收光的起源和演变。生物质燃烧气溶胶包括范围广泛的有机化合物，可能随燃料种类和燃烧条件而变化。由于各种化学和物理过程，有机气溶胶的吸收率在大气中的老化过程中会发生变化。生物质燃烧气溶胶导致空气质量差，并可能改变辐射平衡并影响气候。该项目的目标是更好地了解生物质燃烧气溶胶对空气质量和气候系统的影响。这项工作包括对棕色碳在生物质燃烧排放过程中的初始和演变的光吸收特性进行实验室研究，如辐照、氧化和纳入气溶胶的水相或有机相。重点将放在美国南部大平原地区（SGP）火灾排放的气溶胶上，那里的景观包括草和一些木本物种，如东部红杉。实现该项目的目标包括以下任务：(1)从与SGP位置相关的未开发燃料物种制备生物质燃烧有机气溶胶（BBOA）并确定其光吸收；(2)确定单个BBOA发色团及其配合物和低聚物的光吸收光谱和热力学参数；(3)确定大气老化对生物质燃烧气溶胶光吸收的影响，包括BBOA的化学处理和黑碳的物理处理。总之，这些任务将使人们对生物质燃烧气溶胶吸收光的起源和命运有基本的了解。教育和推广活动包括创建公开的大气化学概念的在线可视化，在博物馆和选定的大学项目中进行大气过程的演示，以及与美洲原住民学生建立研究轮转。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 CAREER project is focused an investigation of the origin and evolution of light absorption from biomass burning aerosol. Biomass burning aerosol includes a wide range of organic compounds that may vary with fuel species and combustion conditions. The absorptivity of organic aerosol is known to change during aging in the atmosphere due to a wide variety of chemical and physical processes. Biomass burning aerosol contributes to poor air quality and can alter the radiative balance and impact climate. The goal of this project is to better understand the impacts of biomass burning aerosols on air quality and the climate system.This effort involves a laboratory study of the initial and evolving light-absorbing properties of brown carbon as biomass burning emissions undergo processes such as irradiation, oxidation, and incorporation into the aqueous or organic phases of the aerosol. The focus will be on aerosol emitted from fires in the US Southern Great Plains (SGP) region, where the landscape includes grasses and some woody species, such as eastern red cedar. Achieving the objectives of the project involves the following tasks: (1) prepare biomass burning organic aerosol (BBOA) from under-explored fuel species relevant to the SGP location and determine its light absorption; (2) determine the spectroscopic and thermodynamic parameters dictating light absorption by individual BBOA chromophores and their complexes and oligomers; (3) determine the effects of atmospheric aging on the light absorption of biomass burning aerosol, including the chemical processing of BBOA and the physical processing of black carbon. Together, these tasks will enable fundamental insights into the origin and fate of light absorption by biomass burning aerosol.Education and outreach activities include creating publicly available online visualizations of atmospheric chemistry concepts, conducting demonstrations of atmospheric processes at a museum and within selected university programs, and establishing a research rotation with Native American students.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.