我国地面O_3、NO_x、SO_2背景值的观测研究

OBSERVATIONAL ANALYSIS OF SURFACE O 3、 NO x AND SO 2 IN CHINA

从１９９４年８月至１９９５年８月，在龙凤山、临安大气污染监测站和瓦里关大气本底基准观象台对Ｏ３、ＮＯｘ及ＳＯ２首次进行了长期的连续观测．初步分析表明：３站地面Ｏ３的平均浓度、月际分布和日变化特征因地理环境、海拔高度和天气条件的不同，表现出明显的差异性．平均地面Ｏ３浓度，龙凤山为３４．８×１０－９，临安为３９．１×１０－９，瓦里关山为４９．３×１０－９．龙凤山和临安的月平均地面Ｏ３浓度分布较复杂，在６～７月和１２月～１月较低，１０月底～１１月初较高．而在瓦里关山，月平均地面Ｏ３浓度变化较平稳，６月份最大，１２月最小．龙凤山和临安地面Ｏ３平均日变化量较大，下午浓度最高，清晨最小；而瓦里关山地面Ｏ３平均日变化较小，上午浓度略低；ＮＯｘ和ＳＯ２的分布具有明显的局地性特征，在龙凤山、临安和瓦里关山，３站的总平均浓度分别为２．７×１０－９（ＮＯｘ）和０．７×１０－９（ＳＯ２），８．１×１０－９（ＮＯｘ）和１６．１×１０－９（ＳＯ２），０．０４×１０－９（ＮＯ２）和０．１５×１０－９（ＳＯ２）．

From August 1994 to August 1995, the continuous in site measurements of surface O 3, NO x and SO 2 have been made in three sites of China which are Lin′an, Longfengshan background stations, and Waliguan baseline observatory. The preliminary analysis of the data indicates that the average concentration, monthly and diurnal change of surface O 3 mainly depend on geographic environment, sea level and weather conditions. During the priods of measurement, the average concentrations of surface O 3 are 34.8×10 -9 in Longfengshan, 39.1×10 -9 in Lin′an and 49.3×10 -9 in Waliguan, respectively. The monthly average concentrations of surface O 3 are quite different in these sites, in Lin′an and Longfengshan, O 3 concentrations show lower in December and January, and in June and July, respectively, and higher from the end of October to early November, while in Waliguan, the monthly variation of O 3 concentration is much smaller, the lowest value in December, and the highest in June. The diurnal variation of surface O 3 concentration shows an obvious diurnal cycle with a maximum in the afternoon and a minimum in the early morning in Longfengshan and Lin′an, but with a small diurnal variation in Waliguan. The distributions of NO x and SO 2 show an* obvious local characteristies, the average concentrations are 2.7×10 -9 (NO x) and 0.7×10 -9 (SO 2), 8.1×10 -9 (NO x) and 16.1×10 -9 (SO 2), 0.04×10 -9 (NO 2) and 0.15×10 -9 (SO 2), respectively in Longfengshan, Lin′an and Waliguan stations.