光化学臭氧日变化特征与其前体物关系的探讨

Relations of Diurnal Variations of Photochemical Ozone to Its Precursors

应用大气光化学模式研究了日最大臭氧体积分数及其出现时刻与其前体物NMHC、NOx体积分数及NMHC/NOx比值的关系。结果表明,影响日最大臭氧体积分数(φO3m ax)脊线位置(EKMA图,Empirical K inetic Modeling Approach)的关键因子是NMHC成份组成比例;日臭氧体积分数达到最大值需要的时间(τO3m ax)与NMHC/NOx比值及NMHC成份组成比例有关,与NMHC、NOx体积分数关系不大。此外,利用该结果解释了近20 a北京日最大臭氧体积分数出现时刻具有不断提前的变化趋势的原因。

The relations of the diurnal peak of photochemical ozone and its occurring time to the ozone precursors （NMHC ,NOx） and the ratio of NMHC/NOx are researched by using an atmospheric photochemical box model. Results show that the most important factor on the peak ozone（ψ0 3max ） ridge＇s slope of EKMA graph is compositions of NMHC. The diurnal peak ozone occurring time （τ0 3max） is dependent on the ratio of NMHC/NOx and compositions of NMHC, but independent on concentrations of NMHC and NOx. The reason of the advancing trend of τ0 3max in Beijing in recent 20 years is explained by the model results.