北京市夏季O3、 NOx等污染物“周末效应”研究

采用了2000-06-25~2000-07-07以及2000-07-26~2000-08-22在北京325 m气象塔观测平台观测到的O3、NOx(NO和NO2)、CO和SO2数据,分析了周末与工作日O3、NOx、NO、NO2、CO和SO2浓度变化的差异及成因.结果表明,除SO2之外,O3、NOx、NO、NO2和CO的周末浓度与对应工作日浓度相关性显著,均通过了显著性水平α=0.05的t检验,相关系数(R)依次为0.99、0.61、0.56、0.80和0.61.交通高峰时段(06:00~08:00)NOx和CO的周末浓度明显低于工作日浓度,该时段NOx和CO的周末浓度与工作日浓度的平均偏差分别为-28%和-9%.O3周末浓度与工作日浓度的回归系数为1.25±0.02.此外,周末O3的最大小时浓度值与最大8 h平均浓度值分别比工作日高23%和26%,表现出十分明显的"周末效应".

Study of the "Weekend Effect" of O_3,NO_x and Other Pollutants in Summer of Beijing

The data of O_3,NO_x(NO and N0_2),CO and SO_2 observed at Beijing 325m meteorological tower from June 25 to July 7,2000 and from July 26 to August 22,2000 are used to analyze the difference of pollutant concentrations on weekends and weekdays, and its causes. Results show that except SO_2,the correlations of O_3,NO_x,NO,NO_2 and CO concentrations between weekends and weekdays are very significant, since they all pass the t-test significance level at α=0.05.The correlation coefficients(R)are 0.99,0.61,0.56,0.80 and 0.61 for O_3,NO_x,NO,N0_2 and CO, respectively. Weekend NO_x and CO concentrations are lower than weekday concentrations in rush hours(06:00～08:00),and the mean deviations for NO_x and CO concentrations are -28% and -9%,respectively.The regression coefficient of O_3 concentrations between weekends and weekdays is 1.25±0.02.Furthermore,the maximum 1-h average O_3 concentration and maximum 8-haverage O_3 concentration on weekends are 23% and 26% higher than those on weekdays, respectively, indicating an obvious O_3"weekend effect".