辽宁中部城市群夏季大气能见度的观测研究

利用2009年6—8月辽宁中部4个城市的观测资料,分析了辽宁中部城市群夏季的季、月、日能见度分布,并探讨了能见度的日变化特征及其影响因子。结果表明:辽宁中部城市群内各城市夏季大气能见度月际变化趋势基本一致,天气系统和大气环境比较均一,具有明显的区域性特征;各城市大气能见度日变化呈明显的单周期谷、峰形分布,06时前后能见度最差,15—16时最好;大气细粒子、水汽和风速都对城市群能见度有一定的影响,其中,大气细粒子是主要影响因子;城市群夏季的低能见度时次,仅有一小部分是由轻雾引发的,而大部分则是由霾天气造成的。

Observational study of atmospheric visibility in summer in the area of multi-cities in central Liaoning Province

Using the observational data of 4 cities in central Liaoning Province from June to August, the mean seasonal, monthly and daily characteristics of visibility is analyzed in this paper. In addition, the diurnal visibility and influence factors are also studied. The results indicate that each city in the area of multi-cities in central Liaoning Province shows the same trend of monthly visibility variety. The weather system and atmospheric environment has generally uniform and regional features.Daily visibility variety of each city presents the distribution of single period peaks and valleys in which the lowest valueis are at 06:00 BT and the highest ones at 15:00-16:00 BT. Furthermore, fine particles, vapor and wind speed all have effects on visibility, among which fine particles are the major factor. Only a small part of the low visibility duration is due to slight fog. It is the haze that causes most of the low visibility events in the area of multi cities in central Liaoning Province.