大连机场一次罕见的连续四天大雾低云过程分析

本文利用常规天气图、探空图和三维中尺度模式,对大连机场2011年6月29日到7月3日出现的连续4天的大雾低云天气进行分析,发现此次大雾低云过程发生同副热带高压的位置和强度变化密不可分:副热带高压中高层的下沉逆温对大雾低云天气的低层稳定层的产生和维持起到重要作用;同时它的西进北抬和东撤南退直接导致大连机场上游天气系统三次槽线东移,进而影响本场。近地面层的水汽辐合和弱冷暖气流交汇为大雾低云天气得以维持提供良好的水汽条件。

Analysis on the Four-day Consecutive Fog/low Stratus at Dalian Airport

The meteorological elements of fog/low stratus whether, which occurred from June 29 to July 3 in Dalian, is analyzed by using conventional weather charts, sounding charts and three- dimensional meso-scale model. The results show that the fog and low stratus whether are strongly as- sociated with the location and intensity of the subtropical high pressure. Subsidence inversion in the high and middle layer of the subtropical high pressure plays an important role in the generation and maintenance of the stable-layer in the low-layer. Meanwhile, the subtropical high pressure that expands westward and northward while contracts eastward and southward which directly leads the trough east- ward for three times at Dalian Airport. The moisture convergence of near-surface layer and weak con- vergence of cold and warm air provide good moisture conditions of the fog and low stratus whether.