Influence of transboundary air pollution into the atmosphere of Kathmandu Valley

Air pollution is a silent public health emergency that respects no political frontiers. Due to this fact, there is always a heated debate among the people of Nepal that more than a third of the pollution in winter is blown in from across the Indian border. The recent pollution episode in New Delhi during November 2019 has panicked the people of Kathmandu Valley. However, contrasting to this fact, some news agencies reported a negligible effect of transboundary pollution, especially in Kathmandu Valley. There are very few scientific studies on transboundary air pollution in Nepal, thus, the level and sources of contribution are still a subject of debate. Long-term air pollution data is needed to take steps for mitigation strategies, awareness campaigns, and advocate for policy change. Our proposed project aims to fill the gap in information about transboundary air pollution between Nepal and India through the integrated method of ground monitoring (Nepal and India), satellite sensor (MODIS-Terra and Aqua), and back-trajectory modelling. Aerosol Optical Depth (AOD) geospatial maps will be generated for each day of the air parcel of backward trajectory movement for two years. The series of AOD maps with back-trajectory modelling gives the visualisation of aerosol movement to the receptor region from the source. This study will help us to find out the potential pollution source and the likely period of maximum influence of transboundary pollution on Kathmandu, Nepal.