福州市大雾发生的环流形势及其气象要素特征

Circulation Pattern and Its Meteorological Element Distribution Feature of Fog in Fuzhou

利用1981年～2005年NCEP再分析资料、常规地面和高空观测资料，统计和分析了福州大雾发生时的天气形势特征。结果表明：福州市的大雾主要发生于12月～次年6月，并集中发生在2～5月的春季；年平均大雾日数无明显的变化周期；850hPa的切变位于南昌和福州之间，气压场呈均压场分布是福州大雾发生的有利形势；大雾发生时，地面处于暖区当中，近地面层大气达到饱和。统计和天气形势分析结果，为大雾天气做了基础研究工作，为实现大雾的客观预报提供依据。

Ncep reanalysis data, surface and high sound data from 1981 to 2005 were used to analyze the circulation pattem and meteorological element distribution feature of fog in Fuzhou. It was shown that the fog taken place in Fuzhou were mostly adjective fog and happen from December to June in the next year, especially in spring season. When fog occurred, there was a shear between Nanchang and Fuzhou in 850 hPa; in surface layer, the ground was in warm area with almost stationary wind; the air above surface was approaching to saturation with steady stratification and inversion layer. All of the above statistic results and synoptic pattem had done some fundamental job and gave great help to objectively forecast the occurrence of the fog in Fuzhon.