NUMERICAL SIMULATION OF THE SEASONAL VARIATION OF TROPOSPHERIC OZONE OVER CHINA

An updated version of the Regional Acid Deposition Model(RADM)driven by meteorologicalfields derived from Chinese Regional Climate Model(CRegCM)is used to simulate seasonal variationof tropospheric ozone over the eastern China.The results show that:(1)Peak Oconcentration moves from south China to north China responding to the changing ofsolar perpendicular incidence point from south to north.When solar perpendicular incidence pointmoves from north to south,so does the peak Oconcentration.(2)In the eastern China.the highest Omonth-average concentration appears in July.thelowest in January and the medium in April and October.The pattern mainly depends on the solarradiation,the concentration of Oprecursors NOand NMHC and the ratio of NMHC/NO.(3)Daily variations of Oover the eastern China are clear.Namely,Oconcentrations rise withthe sun rising and the maximums appear at noon.then Oconcentrations decrease.The highest dailyvariation range of Oappears in summer(40×10in volume fraction)and the lowest in winter(20×10in volume fraction).(4)Daily variations of Oover the western China are not clear.The daily variation range of Oisless than 10×10in volume fraction.