This book examines air pollution of a big city using multi-year and multi-season data from ground-based air monitoring stations and satellite sounding data, which provides more clear and detailed information on the main sources of air pollution, the long-term trend of pollution, the influence of meteorological parameters on pollution levels, and trajectories of polluted air masses. For example, the book shows that particulate matter from local sources is transported from deserts to create air quality challenges. It also analyzes the effects of desert and semi-desert landscapes on high concentrations of pollutants.