“96.1”暴雪期中尺度切变线发生发展的动力诊断Ⅱ:散度和散度变率诊断  

DYNAMIC DIAGNOSES OF THE GENESIS AND DEVELOPMENT FOR MESOSCALE SHEAR LINE DURING “96.1”SNOWSTORM, Ⅱ: DIAGNOSES OF DIVERGENCE AND ITS VARIABILITY

作　　者：张小玲[1] 程麟生[2] 

机构地区：[1]北京气象科学研究所工作,100089 [2]兰州大学大气科学系,甘肃省兰州市730000

出　　处：《高原气象》2000年第4期459-466,共8页Plateau Meteorology

基　　金：国家自然科学基金!(497752 71 )资助

摘　　要：利用引入三相云显式降水方案后改进和发展的中尺度模式MM4模拟输出资料 ,对“96.1”暴雪过程的散度及其变率进行诊断分析。结果表明 ,低空辐合、高空辐散的散度场结构及其演变与暴雪切变线的生成发展及暴雪落区相对应。散度方程计算结果表明 ,低层散度负变率带及其内中心的生成与发展先于切变线辐合区的形成 ,揭示了暴雪降水系统的生成与发展 ,并与未来时刻的降雪强度及落区有较好的对应关系。The divergence and its variability during “96.1” snowstorm were diagnosed using the output data of the improved and developed mesoscale model (MM4), in which a three phase cloud explicit precipitation scheme has been introduced. The results showed that structure and evolution of divergence field with an intensive lower level convergence and upper level divergence were related to the genesis and development of the mesoscale shear line and snowstorm. By calculating the divergence equation, it indicated that the centers and their belts of the negative divergence variability in the lower level was formed and developed before that of the convergence with the strength and region of heavy snowfall 12 hours later.

关 键 词：暴雪 散度变率 三相云显式降水 中尺度模式 

分 类 号：P426.634[天文地球—大气科学及气象学] P458.2