近50年合肥地区大雾分析

Analysis of Heavy Fog in Hefei Area in Recent 50 Years

[目的]分析合肥地区大雾的基本特征,为交通运输部门提供参考资料。[方法]利用合肥气象站的长年代资料序列（主要为1954-2006年）,研究合肥地区大雾的年、月、日变化特征及其持续时间。[结果]合肥地区年平均大雾天数在16 d以上,具有明显的年际变化特点。同时,该地区大雾具有明显的季节特征,主要集中在冬季（12-2月）,而夏季大雾天气较少。该地区大雾的出现时间基本集中在下半夜至凌晨日出前后。在不同持续时间内,合肥地区大雾出现频数的年变化不同。持续时间为2-6 h的大雾在1月出现次数最多,持续时间为6-12 h的大雾在12月出现次数最多,持续时间超过12 h的大雾仅出现在11-2月。[结论]合肥地区大雾基本属于辐射雾。

[ Objective] The research aimed to analyze the basic characteristics of heavy fog in Hefei area and provide reference data for transportation departments. [Method] Based on the long-term data series of Hefei weather station（mainly from 1954 to 2006）, the annual, monthly and daily change charactefistics and the duration of heavy fog in Hefei area were studied. [ Result] The average annual days of heavy fog in Hefei area was over 16 d and it had obvious annual change characteristics. At the same time, heavy fog in Hefei area had obvious seasonal characteristics and it was concentrated in winter （from December to February in next year ） and the heavy fog in summer was little. The occurrence time of heavy fog in this area was concentrated from the time after midnight to the time before and after sunrise in wee hours. In different duration, the annual changes of occurrence frequency of heavy fog in Hefei area were different. The heavy fog with the duration of 2 - 6 h had the most occurrence times in January,while that with the duration of 6 - 12 h had the most occurrence times in December and that with the duration of over 12 h only occurred from November to February in next year. [ Conclusion] Heavy fog in Hefei area belonged to radiation fog basically.