Abstract
The increasing attention to large-scale air pollution has resulted in numerous air monitoring networks and field studies. Trajectory calculations are often usedto understand the behavior of air pollutants and the results of measurements. However the accuracy of trajectory calculations is not well known, especially for the long-range transport in East Asia. In this study, some recent measurement data are used to determine the accuracy of isentropic trajectory model. The separation between isentropic trajectories and three-imensional trajectories derived from meteorological data which have sufficient temporal resolution is used to assess the validity of the isentropic technique. The results indicate that the isentropic trajectories arrived closest the boundary layer sometimes differ greatlyfrom three dimensional trajectories arrived at the surface measurement points. The causes of discrepancy is considered. Although the details of each trajectory do not necessarily reflect the actual path of motion of pollutants, the calculations suggest that the emsumble mode of trajectory analysis provides a useful tool of the relative patterns of large scale air motion.
