一次冬季降雪过程的多普勒雷达资料特征分析

2005年2月17~18日青岛出现了一次大雪过程,通过对多普勒雷达资料的分析,发现多普勒雷达资料很好地揭示了本次降水过程的成因。降水初期,主要为暖湿气团从相对较暖的海面上移动到相对较冷的陆地上冷却凝结产生的降雪,所以强度很弱;在0~2.7km高度上,在倒槽上发展起来的以青岛为中心的中尺度气旋性风场的出现,预示着降水强度的迅速增强和降水量级的改变,该风场的破坏,则预示着降雪强度的迅速减弱;回波强度在30~35dbZ时,降雪强度即可达到较强。

Analysis on Doppler data characteristics of a heavy snow

A heavy snow event occurred at Qingdao on February 17th to 18th, 2005.Doppler data demonstrated its capability in revealing the causes of this event. At theinitial phase, the snow was light, because it was generated while the warm and wet airmoved from the relatively warm sea surface to the cold land surface;Between the altitudeof 0 to 2.7 kilometers, the meso-scale cyclone centered at Qingdao, which was generatedupon a inverted trough, indicated the rapid increase of snow intensity and the change ofprecipitation grade;The destruction of this circulation led to the rapid decrease of snowintensity;The radar echo intensity between 30 and 35 dbZ can indicate a relatively highsnow intensity.