Environmental & Climate Sciences Department Seminar

The Kathmandu Valley in Nepal is home to over 4 Million people, and is one of the fastest growing metropolitan areas in South Asia. It is subject to extreme pollution events due to numerous unregulated localized pollution sources and regional transport from the Indo-Gangetic Plain (IGP). Previous field work has studied gas species, wintertime VOCs and PM in the valley. The Nepal Ambient Measurement and Site Testing Experiment [NAMaSTE] is the first deployment of an Aerosol Mass Spectrometer (HR-ToF-AMS and mini-AMS) in Nepal and allows for a more comprehensive analysis of aerosol species and their source contributions. Source and ambient measurements were made in April 2015, but were interrupted by the Ghorka earthquake. Source measurements were nearly complete, but ambient measurements required additional data. We returned in December and January of 2017-2018 for a multi-site measurement campaign, and again in April 2018 to make additional real-time mobile measurements of aerosol composition throughout the Kathmandu Valley. Clear meteorological influences are observed with regular diurnal wind patterns in the valley. These patterns are key in establishing the influence of regional brick kiln operation with urban air pollution burden in Kathmandu. While organic species dominate the submicron aerosol composition measured throughout Nepal, the inorganic component of the aerosol (e.g. sulfate and chloride) are key species to identify brick kiln emissions and biomass/trash emissions.