Atmospheric Chemistry of Bioaerosols

该项目的重点是描述大气中的生物气溶胶颗粒或生物气溶胶（如真菌、细菌和花粉）的特征。生物气溶胶影响大气气溶胶的物理和化学性质，并在各种与气候相关的大气过程中发挥关键作用，如云和冰核的形成。本研究将解决以下问题：（1）与大气相关的生物物种（真菌、细菌和花粉）的化学组成是什么？(2)生物气溶胶如何影响大气气溶胶质量？(3)生物气溶胶的化学性质如何随着它们在大气中的老化而变化？分析将确定化学成分和变化，由于光化学老化使用氧化流动反应器。将使用高分辨率显微镜和基于DNA序列的技术分析收集的环境生物气溶胶样品的生物成分，同时将使用分析技术对有机化合物进行定量分析，以确定代表主要和氧化生物气溶胶化合物的示踪化合物。（i）确定对生物气溶胶属有特异性的有机示踪剂，确定生物气溶胶以及原生和老化有机化合物对大气有机分子组成的贡献，以及（iii）获得生物气溶胶的源分布，用于化学质量平衡（CMB）受体建模。该奖项反映了NSF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 project is focused on characterizing biological aerosol particles or bioaerosols (e.g. fungi, bacteria and pollen) in the atmosphere. Bioaerosols affect the physical and chemical properties of atmospheric aerosols and play a crucial role in various climate-relevant atmospheric processes, such as the formation of cloud and ice nuclei. This study will improve understanding of the atmospheric chemistry of bioaerosols as well as yield insights on the parameterization of bioaerosols in regional and global climate models.The study will address the following questions: (1) What is the chemical composition of atmospherically-relevant biological species (fungi, bacteria and pollen)? (2) How do bioaerosols affect atmospheric aerosol mass? (3) How do chemical properties of bioaerosols change as they age in the atmosphere? The analyses will determine chemical composition and changes due to photo-chemical aging using an oxidation flow reactor. Collected ambient bioaerosol samples will be analyzed for biological constituents using high-resolution microscopy and DNA sequence-based techniques, while organic compounds will be quantitatively analyzed using analytical techniques to identify tracer compounds representing primary and oxidized bioaerosol compounds.Project results will help: (i) identify organic tracers specific for bioaerosol genera, (ii) determine the contribution of bioaerosols as well as primary and aged organic compounds to atmospheric organic molecular composition, and (iii) obtain source profiles for bioaerosols to be used in Chemical Mass Balance (CMB) receptor modeling.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.