华北中部一次切变线暴雨诊断分析  

Diagnostic Analysis of a Shear Line Rainfall in Central North China

作　　者：王志超[1,2] 王咏青[1] 马鸿青[2] 于雷[2] 

机构地区：[1]南京信息工程大学大气科学学院,江苏南京210044 [2]河北省保定市气象局,河北保定071000

出　　处：《干旱气象》2010年第4期422-429,共8页Journal of Arid Meteorology

摘　　要：利用常规观测资料和NCEP1°×1°再分析资料,对2009年7月16～17日发生在华北中部的切变线暴雨过程进行诊断分析。结果表明:北方冷空气和西南暖湿气流在华北中部交汇,为暴雨的发生提供了有利的天气背景条件。暴雨落区出现在低空急流的前方和左前方,切变线附近。锋生函数表明冷暖空气聚集的程度,对诊断强降雨发生的时段和落区有一定的指示意义。温度平流分析显示暴雨过程中存在干侵入现象,强降水发生在低层暖平流向上倾斜抬升、高空冷平流柱向下侵入的时段,北方低层冷空气起"冷垫"的作用。By using the conventional observation data and NCEP reanalysis data,the shear line rainfall occurred in the central North China on July 16-17,2009 was analyzed. Results demonstrated that： （ 1） The northern cold air met with southern warm wet air in central North China,which provided the favorable weather background conditions for the heavy rain. （ 2） The strong rainfall took place on the left front and front side of a low level jet stream and in the vicinity of a shear line. （ 3） Frontogenesis function showed the gathering intensity of the cold and warm air,which can indicate the rainfall period and rainfall area. （ 4） By analyzing the temperature advection,there existed dry intrusion phenomena and the strong rainfall occurred during the period of the low level warm advection tilting upwards and the high level cold advection intruding downwards,northern low level cold air acted as ＂ cold cushion＂ for the process.

关 键 词：低空急流 切变线 锋生函数 干侵入 

分 类 号：P458.121.1[天文地球—大气科学及气象学]