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中光吸收的起源和演变。生物质燃烧气溶胶包括可随燃料种类和燃烧条件而变化的各种有机化合物。已知有机气溶胶的吸收率在大气中老化期间由于各种各样的化学和物理过程而改变。燃烧生物质的气溶胶导致空气质量差，并可能改变辐射平衡和影响气候。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，包括在实验室中研究生物质燃烧排放物经过辐照、氧化和与气溶胶的水相或有机相结合等过程后，棕色碳的初始和不断变化的吸光特性。重点将放在美国南部大平原（SGP）地区火灾排放的气溶胶上，该地区的景观包括草和一些木本物种，如东部红雪松。实现该项目的目标涉及以下任务：（1）从与SGP位置相关的未开发燃料种类制备生物质燃烧有机气溶胶（BBOA），并确定其光吸收;（2）确定指示单个BBOA发色团及其复合物和低聚物光吸收的光谱和热力学参数;（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。这些任务将使人们对生物质燃烧气溶胶的光吸收的起源和命运有一个基本的了解。教育和推广活动包括创建大气化学概念的公开在线可视化，在博物馆和选定的大学课程中进行大气过程的演示，该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识产权进行评估来支持。优点和更广泛的影响审查标准。

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.