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

Drexel University, Philadelphia PA

Investigators

Abstract

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.