沈阳地区霾的环境特征研究

Study on environmental characteristics of haze in Shenyang

利用沈阳市1961—2009年的气象资料,分析了霾天气出现的年季特征及其天气形势特征。利用边界层气象资料与污染物质量浓度资料对特定的霾过程从边界层到污染物质量浓度条件进行了分析。结果表明：沈阳地区霾的出现呈现逐年上升的趋势,近5 a平均每年为120 d左右,目前霾天数已经占到了全年的30%~40%。冬秋季节出现霾天气较多,秋冬两季霾日数占全年霾日总数的75%。凌晨到上午是霾出现的高发期,02—08时霾出现频率占总霾数的44.5%。霾的出现主要发生在冬秋季节冷空气势力不强,大气扩散能力较弱,边界层出现逆温时刻。接地逆温层厚度常常稳定在200~300 m高度左右,PM10质量浓度与能见度（霾）呈负相关,相关系数-0.402 7。风速与能见度（霾）呈正相关,相关系数为0.886 4。

According to meteorology data during 1961-2009,annual and seasonal characteristics of haze occurrence was analyzed.Meanwhile,base on data of boundary layer and pollutant in haze,boundary layer meteorology condition and pollutant concentration were analyzed as well.The results indicate that winter and fall are period of haze occurrence frequently and frequency ascends annually in Shenyang area.In recent 5 years,mean annual haze days are around 120,accouting for 30%~40% in whole year days.Haze mainly occurs in winter and fall,accounting for 75% in whole year haze days.Haze occurs mainly from night to morning,accounting for 44.5% during 2：00-8：00 in a day.Moreover,haze occurs on condition that cold air and dispersion ability are weak and thickness of thermal inversion usually exists between 200~300 m.Besides,PM10 concentration and wind speed are closely related to visibility and haze,and related coefficient are-0.4027 and 0.8864,respectively.