Yasuo Yoshikawa

Estimation of Air Quality by Three-Dimensional Air Simulation Model. Effect of Low Emission Vehicles on Air Quality Improvement in the Greater Los Angeles Area.

Effect on air quality improvement in the South Coast Air Basin (SCAB) around the Greater Los Angeles area in California State by introduction of low emission vehicles is studied using a three-dimensional numerical simulation model which solves the urban-scale atmospheric diffusion equations and photochemical reactions. By replacing all the light duty vehicles (LDVs) with ZEV, the vehicles which satisfy the strictest regulations, total mass emission of CO from automobiles will be reduced by 83%, NOx by 66%, and ROG by 85%. Ozone concentration over the SCAB is found to be reduced by the introduction of the low emission vehicles. In the case that all the LDVs are replaced with 1994 regulation level vehicles, TLEV, LEV and ZEV, the maximum ozone concentration will be reduced by 14%, 17%, 18% and 20%, respectively.