合肥市雾日气象条件分析

Analysis of weather conditions for fog in Hefei

利用合肥市气象观测站2005—2009年常规观测资料,统计分析了该市雾的月、季变化,及雾日地面气象要素特征;同时,应用后向轨迹和聚类分析的方法,研究了雾日大尺度输送特征。结果表明,合肥雾日数12月最多,7月最少;雾日局地气象条件表现为高湿、微风、偏东或西北风向;合肥雾日与输送形势关系密切,雾日近地层(10 m)以偏东方向的轨迹最多,在边界层中上部(1 000 m)以西南轨迹和本地轨迹最多。

The monthly and seasonal variation of fog in Hefei and related surface weather elements characteristics were analyzed using conventional observation data from 2005 to 2009. Back-trajectory and cluster analyses were used to study the large scale transport characteristics on fog days. The results show that the number of fog days was the muximum in December, but it was the minimum in July. The weather conditions of fog can be characterized by high humidity, breeze and easterly or northwest wind. The fog occurrence was closely related to the transport pattern. The fog was associated with easterly （ from east） trajectory at the ground level （10m）, southwesterly and local trajectory at upper boundary layer （ 1000m）.