鼎湖山森林地区臭氧及其前体物的变化特征和分析

通过对鼎湖山森林地区近地面O3和NOx浓度、太阳辐射、气象参数等为期一年的观测和资料分析,给出了地面O3和NOx浓度、太阳辐射的变化规律及其相互之间的关系.地面O3、NOx、CO、SO2浓度以及紫外辐射、太阳总辐射等有明显的日变化和季节变化.不同因子对O3的敏感性试验结果表明,晴天和实际天气,O3浓度对NO、NO2浓度的变化最为敏感,其次是水汽、气溶胶,最后是紫外辐射.所有因子的变化均引起O3在湿季比干季更大的变化率,因此在研究臭氧化学和光化学时,应该考虑水汽以及OH自由基的重要作用.对于晴天和实际天气的逐时值和日平均值而言,O3浓度与NO2/NO之间存在很好的正相关关系,比值NO2/NO可以作为判断O3峰值出现的一个指标.O3极值的出现既受NO和NOx影响,也受气象因素(温湿度、云、风、雾、降雨)和辐射的影响.周末O3、NOx浓度及NO2/NO有规律的增大,表明实验地点的大气受到人为污染源的影响.

The Variation Characteristics and Analysis of Ozone and Its Precursors in the Dinghushan Mountain Forest Area

Based on the observational data and analysis of surface ozone, NO x, solar radiation, and meteorological parameters for one year in the Dinghushan Mountain biosphere reserve, the variation regularity of surface ozone, NO x, solar radiation and their relationship were given. O 3, NO x, CO, SO 2, UV and global solar radiation exhibited an evident diurnal and seasonal variation. The results of sensitivity test for all factors to ozone show that ozone is more sensitive to the changes of NO and NO 2, then water vapor and aerosol, and finally UV in clear and all sky conditions. The changing rates of O 3 caused by the changes of each factor (NO, NO 2, water vapor, aerosol, and UV) is bigger in wet season than that in dry season, implied that the important roles of water vapor and OH radical in O 3 chemistry and photochemistry should be considered. Good positive correlations were found between O 3 and NO 2/NO for their hourly and daily values in clear and all sky conditions,then NO 2/NO can be used as an indicator for high O 3 formation. The formations of maximum and minimum O 3 are influenced by not only NO and NO 2, but also meteorological conditions (including temperature, humidity, cloud, wind speed, fog, precipitation and etc.) and solar radiation. The regular increases of O 3, NO x, and NO 2/NO at weekends indicate that observation site is influenced by anthropogenic pollution from the traffic.