Analysis Of The Characteristics Of Surface Ozone And Carbon Dioxide In Clean Area Over Qinghai-Xizang Plateau

Based on the data of surface ozone, carbon dioxide, solar radiation, total ozone, climate observation as well as the boundary layer meteorological elements in 1994.11-2002.7, the characteristics of surface ozone and carbon dioxide are analyzed over Waliguan by statistic method. The result shows that the surface O3 has significant seasonal variation over the clean area in Qinghai-Xizang plateau, and it keeps increasing with low speed, surface O3 concentration in spring is higher than that in winter, the maximum is in June while the minimum is in January. The daily variation of surface O3 is different under different weather condition, the variation of surface O3 in spring, autumn and summer is almost same when it is clear. In spring and autumn, under the condition of clear sky, its value is higher than that in cloudy or rainy /snowy day, while its variation is not obvious in winter and summer; in rainy and snowy season, the variation of surface O3 in spring, autumn and winter is insignificant, bnt in summer, it is significantly different from other seasons, daily difference is the highest among all seasons, it has some important relationship with rain/snow, moreover, the function of rain and snow to the varation of surface O3 is different. Regional photochemical reaction is weak over this area, to a great extent, the atmospheric background condition influences to the variation of surface O3, Tthe variation of vertical wind speed is significant to surface O3, from seasonal distribution of vertical wind, it appears upward air current in winter, spring and autumn, repectively, while it is mainly downward in summer, it is favorable to the O3 transport from stratosphere layer. At Walilguan, the variation of humidity impacts a little on surface O3, the relationship between surface O3 and wind speed is relatively complicated, by correlation statistic analyze, it is sure that the wind speed is not one of the important factor. The long distance transport of pollutant from the direction of SE, ENE and etc, has some influences to the variation of surface O3 over Waliguan, due to the short life of precursors, and the long distance between two sites as well as the weak photochemical reaction over this area, the influence of wind direction is not so important. The total ozone distribution over stratosphere layer in china appears obviously seasonal variation tendency, that is, the value of total ozone in spring and winter is higher than that in summer and autumn, while the maximum of surface O3 over Waliguan is in summer, which is relatively late, approximately 2-3 months, it illustrates that the vertical transport from stratosphere has important effect to the increasing of surface O3. Compare to the Izana global observatory, surface O3 has been slowly increasing, but not so stable, it also showsthat the monitoring of surface O3 has global scale, and its data has comparability in the world.The monthly and seasonal variation of atmospheric carbon dioxide over Waliguan is distinct, and keeps increasing with the speed of 1.6614ppm/a. the maximum is in the middle of April to the beginning of May while the minimum is in late July to the beginning of August. Due to the different plant and ground condition around observatory, the variation of CO2 is different, the CO2 distribution near the ocean and mountain is also different, among the mountain station, its variation is related to latitude.