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arious fields of physics, such as astronomy, cosmology, and solar physics, are dedicated to studying numerous fascinating phenomena over the centuries. In every discipline, the study involves theoretical frameworks, simulations, experiments, and observational methods. There are still many phenomena that are mysterious to us, and our understanding of them is still incomplete. Bringing all the ideas together, and discussing them on one platform may provide us new insights. In this division, we welcome studies from the following disciplines.
- Computational, and High Energy Astrophysics
- Cosmology, Dark Matter, and Dark Energy
- Extragalactic Astronomy and Galaxy Formation and Evolution
- Magnetospheric Physics
- Planetary science
- Solar Physics and Heliophysics
- Star Formation and Interstellar Medium
Air Pollution Transport and Formation of Pollutant Fields Over the Major Urban Centers in the Complex Terrain of Nepal Himalayan: Prospects of Ensuring National Ambient Air Quality Standard
Unacceptable levels of air pollution in and around the urban centers like Kathmandu Valley and Lumbini that accommodate large proportion of national population and world heritage sites is of serious concern. Development of air pollution control system for these regions, located in the complex terrains of Nepal Himalaya, remained a challenge. Resolving the meteorological flow fields, air pollution emission activities and the dynamics of pollutants down to kilometer scale horizontal grids, present study has paved the way to ensure the national air quality standard in and around these urban centers. Meteorological flows and air pollution dynamics over these regions have been numerically simulated and are verified with field observations. The study reveals that air pollution dispersion power of both the regions, typically determined by the prevailing meteorological conditions, is very poor, particularly, during the long dry season. Present emission loadings into the immediate atmosphere of both the Kathmandu and Lumbini region are far beyond their carrying capacities. The National Ambient Air Quality Standard can be met by limiting the emissions from domestic, transport and industrial sectors, respectively, to 20, 30 and 40% of the current emissions over the Kathmandu valley and 50, 50 and 30% for Lumbini region with respect to the particulate pollutant PM2.5.