摘要
利用珠江三角洲地区的地面加密观测资料，揭示了影响该地区的一类中小尺度天气系统──锋后冷空气涌，并详细分析了它的地面结构和天气影响。结果表明，这类对流系统非常相似于热带飑线，往往给三角洲地区带来突发性暴雨，但却不易产生强风。该系统的水平尺度很小，只有３０－６０ｋｍ，持续时间达４小时，移速快，约为每小时６０ｋｍ，移向定常，并且它在进入三角洲地区时发展加强，而在移出时减弱消失。和经典的飑线结构的差异在于它是冷性中高压前部激发的强正变压区直接形成了地面辐散外流、飑锋和与之相联系的对流天气，当二者在移动中逐渐相脱离时，正变压区减弱，对流系统也随之消亡。
With intensive surface observations for the area of Pearl River Delta, a local meso-and-small-scale weather system,cold air surge from the rear of the front,is identified and analysed in detail for determination of its surface structure and effects on weather. The result shows that the convective system acts in a manner very close to tropical squall lines by bringing explosive hard rain in assication with weak tendency for strong winds for the area of interest. It covers 30-60 km horizontally and lasts up to 4 hours, moving at 60 km/h in constant direction. It would be enhanced or weakened as it migrates into or out of the area. It is the strong isallobric area excited by the front edge of cold mesohigh that directly causes the surface divergent outflow, squall front and assciated convective weather, a contrast against classic squall struture.The isallobaric area weakens and the convective system disaipates as a result as they gradually separate from each other in motion.
出处
《热带气象学报》
CSCD
1994年第3期222-230,共9页
Journal of Tropical Meteorology
