Abstract
Studies on three-dimensional observation and model analysis for urban and wide aerial air pollution in the present three decades are reviewed mainly focusing on author's studies.
Mechanisms of photochemical air pollution formation were clarified from a series of field study in Kanto area. That is, under the condition of weak atmospheric pressure gradient polluted air masses are transported inland due to sea breeze. In nighttime this moves to off shore due to land breeze. In day time vertical convection predominates and pollutants are mixed well. On the other hand in nighttime previous days pollutants remains aloft and this aged secondary pollutants are entrained to the mixing layer of the next day. The existence of large-scale circulation of air pollution between inland mountainous area and Pacific Ocean was also found.
From the studies in northern Kyushu area, it was found that the effects of stratospheric ozone intrusion, transported air pollution from the continent, locally emitted air pollution and pollutants from volcanic eruption are mixed.
From the aircraft observation and model studies in Kansai area for spring time increase in nitrogen dioxides, it was found that transported ozone to this area plays an important role to the oxidation process of nitric oxide which are mainly emitted in Osaka bay area.
From the air pollution trend analysis and model assessment wide spreading and homogenization of air pollution was observed; that is in recent year daily maximum concentration of oxidant are frequently observed in inland both in Kanto and Kansai areas.
