Mountain meteorology and its effects on transport and transformation of air pollutants

The effects of mountains on the concentrations of air pollutants over the Earth's atmosphere were investigated. Answers are provided to the following questions: (1) How do mountains affect the photolysis rate parameters of trace gases? (2) How can the emission rates of air pollutants be characterized over the western United States according to population? (3) Can mountains create upward air motions that may lead to the longrange transport of trace gases during winter? (4) How do mountains affect the nighttime mixing ratios of trace gases including ozone during winter?; The research was conducted using several techniques for the western U.S. Actinic flux was measured for the calculation of photolysis rate parameters. The Tropospheric Ultraviolet-Visible radiation model (TUV 4.2) was used for the radiation parameter simulations such as irradiance, actinic flux, and photolysis rate parameters. Emission rates were obtained and processed from United State's Environmental Protection Agency (U.S. EPA) and California Air Resource Board (CARB). The online coupled 3-dimensional atmospheric chemistry model (MM5-chem) was used for numerical simulations.; This research showed that mountainous terrain has a strong effect on actinic flux, pollutant transport and their mixing ratios over both local and regional spatial scales. Emissions are transformed over the mountains by photochemical reactions to produce air pollution and the mountains affect the rate of these transformations through their effect on photolysis rates. Mountains cause vertical motions that transport the transformed air pollutants to the middle and upper troposphere where they may be transported over regional and global scale distances and affect climate.