利用1980-2015年沈阳地区地面气象观测资料,对近36 a沈阳地区采暖期霾天气的年、日变化及气象要素的变化特征进行了分析.结果表明:1980-2015年沈阳地区采暖期霾日数呈平稳增加的趋势,霾天气主要出现在上午的07-11时,夜间和午后霾天气较少出现;霾天气持续时间多为7h以内.沈阳地区采暖期霾天气发生时,地面相对湿度较高,主要集中在70.0%-90.0%之间;地面风速主要为3.0 m·s-1以下且以静风为主,风向以偏东风为主.利用地面气象观测资料计算的混合层高度对不同等级霾天气的指示效果较好:重度霾天气混合层高度主要集中在0-400 m高度层内,中度霾天气混合层高度主要集中在0-600 m高度层内,轻度霾天气混合层高度主要集中在200-600 m高度层内.加强天气条件监测和预测可以有效预测霾天气,并采取有效应对措施减轻霾天气的影响.
The annual and daily variation of haze weather during heating periods,and the variation of the corresponding meteorological elements were analyzed using the ground observation data in Shenyang from 1980 to 2015.The results show that the number of haze days during heating periods demonstrates a steady increasing trend from 1980 to 2015.The haze weather mainly appears from 07:00 to 11:00 a.m.,mostly disappears at night and in the afternoon.The duration of most of haze weathers is within 7 hours.When the haze weather happens during heating periods,the relative humidity on the ground is high and regularly in the range of 70%-90%.The wind on the ground is often static,its speed is commonly less than 3.0 m· s-1,and its direction is mostly easterly.The height of mixing layer calculated by the surface observation data has a good indication effect to the different ranks of haze weathers.For the severe haze weather,the height of mixing layer is frequently within 0-400 m;for the moderate one,it is within 0-600 m;and for the mild one,it is within 200-600 m.To strengthen the monitoring and forecasting of weather conditions can help to effectively predict haze weathers and to take useful measures to reduce the haze influence.