2007年7月7—9日淮河流域梅雨锋雨带特征分析

The analysis on the feature of the rain-band along Meiyu front in Huaihe River Basin from July 7 to 9,2007

针对2007年7月7—9日发生在淮河流域的暴雨,采用NCEP1°×1°客观分析资料、6h地面观测降水资料,对此次降水过程中雨带发生、发展进行天气动力学分析。结论如下:(1)暴雨区位于高空急流入口区南侧、南亚高压辐散场东侧,该区域对流层高层为反气旋控制区,有利于低层低值系统的发展;(2)处于非热成风不平衡状态下的低空强急流带形成以后,对于雨带分布以及暴雨发展产生重要影响;(3)视热源、视水汽汇廓线在垂直方向上的变化,体现了水汽凝结潜热释放加热环境大气的作用;(4)基于p坐标系的比湿垂直输送正值带可以较好地示踪雨带移动。

In reference to the rainstorm which happened in Huaihe River Basin from July 7 to 9,2007,based on the data of NCEP1°×1° and the 6 h precipitation observation,weather analysis during the precipitation process was presented in this paper.The conclusions are as follows：（1） The rainstorm band was located in the south of upper jet stream＇s entrance region and in the east of the field of divergence of South Asia high.The upper part of troposphere in this area is anti-cyclone control region which helps develop low-pressure system in the low altitude.（2） The jet stream band in the low altitude under the unbalanced situation of non-thermal-wind greatly affects the rain-band distribution and the development of rainstorm.（3） The change of apparent heat source and apparent moisture sink in the perpendicular direction reflects the effects,such as vapor condensation,latent heat release and heating of atmospheric environment.（4）The positive value band of vertical transportation of specific humidity,based on p-coordinate system,reveals quite well the movement of the rain-band.