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

该项目是由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具有全球意义的气溶胶和痕量气体源制定新的大气排放因子。更好地估计气溶胶和气体排放量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。改进的排放系数也将用于区域化学迁移模型，以评估该区域的各种减轻污染战略，将在尼泊尔和不丹部署两台气溶胶质谱仪，这将是该区域首次使用先进的气溶胶质谱仪仪器。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）和直接源测量（使用小型气溶胶质谱仪）。研究的目标是：（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，使用烟尘颗粒气溶胶质谱仪对亚微米气溶胶的组成、来源、二次形成和每日趋势进行表征和量化;（2）分配有机气溶胶、光吸收碳质组分和环境气溶胶中的金属物质;以及（3）对采样不足的燃烧源（例如垃圾燃烧、砖窑等）进行源表征和质谱指纹识别。使用一个迷你气溶胶质谱仪除了目前的仪器套件资助这项工作。 PI还将评估氧化有机气溶胶与奇氧的比率，以帮助理解和/或限制该区域二次有机气溶胶形成的可能性。

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.