Ambient and Source Characterization of Aerosol Size and Composition in Nepal and Bhutan using High-Resolution Aerosol Mass Spectrometry

该项目是由美国国家科学基金会资助的一个更大的合作项目（牵头提案AGS-1349976）的一部分，该项目旨在为南亚采样不足的气溶胶和具有全球意义的微量气体开发新的大气排放因子。更好地估计气溶胶和气体排放对于预测亚洲未来经济发展可能导致的空气质量和气候变化非常重要。改进的排放因子也将用于区域化学运输模型，以评估该区域的各种缓解污染战略。两台气溶胶质谱仪（AMS）将被部署到尼泊尔和不丹，这将是该地区首次使用先进的AMS仪器。这些仪器将分为固定地点测量（使用烟尘粒子气溶胶质谱仪，SP-AMS）和直接源测量（使用微型气溶胶质谱仪，mAMS）。本研究的目的是：(1)在尼泊尔加德满都环境固定站点监测的其他补充测量的背景下，利用烟尘颗粒气溶胶质谱仪表征和量化亚微米气溶胶的组成、来源、二次形成和每日趋势；(2)利用正矩阵分解等技术对环境气溶胶中有机气溶胶、吸光碳质组分和金属组分的来源进行分配；(3)对欠采样的燃烧源（如燃烧源）进行源表征和质谱指纹图谱。垃圾焚烧，砖窑等)，除了目前为这项工作提供资金的一套仪器之外，还使用了一个微型气溶胶质谱仪。PI还将评估氧化有机气溶胶与奇氧的比例，以帮助了解和/或限制该地区二次有机气溶胶的形成潜力。

This project is part of a larger collaborative project funded by NSF (Lead Proposal AGS-1349976) to develop new atmospheric emission factors for under-sampled sources in South Asia of aerosols and trace gases of global significance. Better estimates of aerosol and gas emissions are important for predicting changes in air quality and climate that might result from future economic development in Asia. Improved emission factors also will be used in regional chemical transport models to assess various pollution mitigation strategies for the region.Two aerosol mass spectrometers (AMS) will be deployed to Nepal and Bhutan and be the first use of sophisticated AMS instrumentation in the region. The instruments will be divided between fixed site measurements (using a Soot-Particle Aerosol Mass Spectrometer, SP-AMS) and direct source measurements (using a mini-Aerosol Mass Spectrometer, mAMS). The objectives of the research are to: (1) characterize and quantify the submicron aerosol composition, sources, secondary formation, and daily trends using a soot-particle aerosol mass spectrometer in the context of other complementary measurements from ambient fixed site monitoring in Katmandu, Nepal; (2) apportion sources of organic aerosol, light absorbing carbonaceous components, and metallic species in ambient aerosol using techniques such as positive matrix factorization; and (3) conduct source characterization and mass spectral fingerprinting of under-sampled combustion sources(e.g. garbage burning, brick kilns, etc.) using a mini-Aerosol Mass Spectrometer in addition to the current suite of instruments funded for this work. The PI will also evaluate the ratio of oxidized organic aerosol to odd-oxygen to help understand and/or bound the secondary organic aerosol formation potential in this region.