Abstract
The estimation of the contribution of long-range transport of the pollutants from East Asia to the urban pollution in Japan was performed by using the chemical transport model. Fine model domain which can resolve the urban emission area was nested within the coarse model domain which covers whole East Asia where the amount of emission is increasing rapidly with an economic growth. We investigated the seasonal variationof the contribution of long-range transport on the tropospheric ozone concentration during January to June, 2004 by comparing the calculation which includes all emissions over East Asia and the calculation with no emission except Japan. As a result, the contribution of the long-range transport on the clean region is larger than that on the urban pollutedregion. Average contribution on the ozone concentration was 5-8 ppb on the ground. This is 20-30% of the average background ozone concentration, and 10% of the environmental standard (60ppb). Especially, from March to May, contribution is large and there is a risk of increasing the damage to an ecosystem. If the NOx, emission in the Asian continent doubles by further economic development, the contribution of the long-range transport will become more severe.
