A trajectory model for air pollution studies.

摘要

In a Lagrangian model, air pollutant transport is strongly affected by wind velocity and direction. Atmospheric dispersion has different patterns and also the dispersion model has different results by wind fields. Trajectory is a very useful tool for air pollution modeling research because it represents a general wind flow during the modeling time. For the present study, a trajectory model developed by Daughenbaugh (1996) is modified for air pollution studies. Since air pollution transport is affected by complex terrain, the trajectory model needs to consider the effect of complex terrain.; For the sensitivity tests, the tracer potential method, developed by Koracin et al. (2000), and the trajectory concentration method were used. Tracer potential is a weight function which depends on the distance between trajectory and receptors and the concentrations at receptors. In general, higher tracer potential value implies a more successful wind field. Tracer potential values between the original trajectories using original wind data and other trajectories using modified data were compared. Trajectory concentration using interpolated surface concentration at a trajectory is another method used to evaluate wind field. With these methods, it is possible to evaluate and see the properties of the trajectory model.; For the sensitivity tests, the trajectory model uses the meteorological data generated from Fifth-Generation Penn State/NCAR Mesoscale Model (MM5) in the project named the Project Measurements Of Haze And Visibility Experiment (MOHAVE) conducted in 1992.