Advanced Characterization of Tropospheric Sources

该项目将使用一种新的在线、高分辨率、高特异性、高灵敏度质子转移飞行时间质谱仪（PTR-TOF-MS）表征火灾排放的气相和颗粒相半挥发性有机化合物（SVOC）和气相挥发性有机化合物（VOC）。许多反应性SVOC和VOC将被识别和量化，以更好地表征烟雾的整体化学和物理特性，更好地了解生物质燃烧羽流中观察到的主要变化，并改进光化学模型。将开展三项主要活动：（1）在美国林务局维持的一个大规模生物量燃烧模拟设施中对重要的火灾类型进行高质量的模拟。(2)在加州大学滨江大气模拟室中，结合高分辨率气溶胶质谱和许多其他测量，对生物质烟雾老化的前3至4小时内VOC以及气相和颗粒相SVOC的变化进行定量。(3)在移动的实验室中安装其他仪器，用于探索性地测量飞机起飞和着陆时以及植被、垃圾燃烧和地热源的排放。该项目将导致对地球上最大的痕量气体和颗粒来源之一生物质燃烧的排放量进行更准确的估计。特别是，将提供臭氧和气溶胶前体的新数据，这对大气建模者和空气质量官员非常重要。这些实验将测量第二和第四大类生物质燃烧（分别为烹饪火灾和作物残渣火灾）中两种重要的生物质燃烧示踪物（氰化氢和乙腈）的排放量。示踪剂可用于源解析，这可以导致改善空气棚管理。化学形态、烟雾演变和来源归属方面都与公共卫生、区域能见度和气候有关。该项目将支持一名研究生进行测量，并将在全球测地系统-化学全球化学迁移模型框架内探索最重要的新数据的更广泛影响。合作将涉及其他机构，如加州大学、滨江大学、蒙大拿州立大学、美国地质调查局和美国林务局。

This project will characterize the gas and particle phase semi-volatile organic compounds (SVOC) and the gas-phase volatile organic compounds (VOC) emitted by fires using a newly available, on-line, high resolution, high specificity, high sensitivity Proton-Transfer Time-Of-Flight Mass Spectrometer (PTR-TOF-MS). Many reactive SVOC and VOC will be identified and quantified than ever before to better characterize the overall chemical and physical properties of smoke, to better understand the major transformations observed in biomass burning plumes, and to improve photochemical models. Three main activities will be undertaken: (1) High quality simulations of important fire types in a large-scale biomass burning simulation facility maintained by the United States Forest Service (USFS). (2) Quantification of the changes in the VOC, and both the gas and particle phase SVOC, during the first 3 to 4 hours of biomass smoke aging in the University of California, Riverside atmospheric simulation chamber in conjunction with high-resolution aerosol mass spectrometry and many other measurements. (3) Installation in a mobile lab with other instruments for exploratory field measurements of the emissions from aircraft during take-off and landing as well as from vegetation, garbage burning, and geothermal sources. The project will lead to more accurate estimates of the emissions from one of Earth's largest sources of trace gases and particles, biomass burning. In particular, new data will be available for ozone and aerosol precursors, which are of great interest to atmospheric modelers and air quality officials. The experiments will measure the emissions of two important biomass burning tracers (hydrogen cyanide and acetonitrile) from the second and fourth largest types of biomass burning (cooking fires and crop residue fires, respectively). The tracers can be used for source apportionment, which can lead to improved air shed management. The chemical speciation, smoke evolution, and source attribution aspects are all relevant to public health, regional visibility, and climate. The project will support a graduate student who will carry out the measurements and will also explore the broader impact of the most significant new data within the framework of the GEOS-Chem global chemistry transport model. Collaborations will involve other institutions such as University of California, Riverside, Montana State University, the U.S. Geological Survey, and the U.S. Forest Service.