暴雨中不同尺度天气系统的分离及其相互作用  

Seperation of Different Scale Weather System in Heavy Rain and Their Interaction

作　　者：张红 杨福全 

机构地区：[1]暴雨监测与预报国家重点实验室 [2]北京大学地球物理系

出　　处：《北京大学学报（自然科学版）》1997年第1期77-84,共8页Acta Scientiarum Naturalium Universitatis Pekinensis

基　　金：国家重点课题<暴雨过程中大尺度和次天气尺度系统的相互作用>资助

摘　　要：利用水平平滑滤波方法对不同等压面上大中尺度场的分析结果表明：在１９９１年７月１—５日的暴雨过程中，从高层到低层青藏高原北部有一急流中心，急流中心位于４０°Ｎ附近。和这次暴雨过程直接对应的急流中心位于２９°Ｎ附近。１—５日这两个急流中心均稳定少动且中心风速比常年大。大范围降水区中的强暴雨中心和中低层的流场、风场辐合区以及扰动低压中心吻合较好。低层等压面上大中尺度系统相互作用项的区域平均值对７００ｈＰａ中尺度系统发展的贡献最大，高层２００ｈＰａ和中层５００ｈＰａ贡献数值接近。The horizontal filtering technique is employed to seperate meso scale field from large scale field for a case of heavy precipation over Yangzi river ocurred on 1-5 July 1991.The northern large scale jet stream has a maximum velocity center exceeding 50m/s on 200hPa. Meanwhile,the southern jet stream corresponding to the large scale precipitation area,has a maximum wind velocity on 500hPa exceeding 20m/s. It is also found that when the meso scale center of high field and wind vector field are nearly the same, a heavy rain center is always located. Finally, the contribution term to the development of meso scale low on 700hPa at different levels are evaluated.It is found that 700hPa term is the biggest, while 500hPa and 200hPa terms have the same magnitude. They have same variation step.

关 键 词：平滑滤波 暴雨 天气系统 分离 相互作用 

分 类 号：P458.121.1[天文地球—大气科学及气象学]