Shinichi Okamoto

Validation of an air pollution model for the Keihin area

Abstract This paper describes a dispersion model for a highly polluted region including Kawasaki, Yokohama and part of Tokyo. The models were based on the Gaussian plume dispersion equation and on the steady model for the calm condition. Hourly values for 3 months at 11 measurement points were used for validation of the calculated results. The validation also involved calculation of the correlation coefficients of hourly values and daily average values, the root mean square error and comparison of pcrecntile-concentration (P-C) curves and arrowhead charts.

A trajectory plume model for simulating air pollution transients

Abstract An air quality simulation model that is simple, yet capable of accurately estimating concentrations under unsteady meteorological conditions, has been developed. This trajectory plume model uses the Gaussian plume equation, but has an applicability that is approximately as wide as the Lagrangian puff model. The plume axis is represented by a series of straight-line plume segments. The performance of this model was evaluated by comparing it with other diffusion models. A comparison between simulation results using the present model and those using integrated puff and Eulerian diffusion models for three different metropolitan areas (one in Japan and two in the U.S.) has indicated that a simple trajectory plume model performs as well as the two other more complex models in simulating pollutant dispersion under complicated meteorological conditions such as those which occur during the transition period from a sea breeze to a land breeze.

Modeling and Simulation of a Practical Air Pollution Model at Signalized Intersections

Abstract This paper describes a practical diffusion model capable of providing estimates of concentrations at the intersections. For the verification of this model, simulations have been done for the seven intersections in Tokyo metropolitan area.