舟曲泥石流天气过程中云团合并的卫星观测  

Cumulus Merging in the Massive Mudslide of Zhouqu Using Meteorological Satellite Data

作　　者：黄勇[1,2] 覃丹宇[3] 

机构地区：[1]安徽省气象科学研究所,合肥230031 [2]安徽省大气科学与卫星遥感重点实验室,合肥230031 [3]国家卫星气象中心,北京100081

出　　处：《应用气象学报》2013年第1期87-98,共12页Journal of Applied Meteorological Science

基　　金：国家自然科学基金项目(40905019;40975023);公益性行业(气象)科研专项(GYHY200906003)

摘　　要：利用极轨和静止气象卫星红外云图资料,对2010年8月7日甘肃舟曲发生的特大泥石流天气过程中出现的对流云合并现象进行分析。从卫星监测结果来看,多个对流单体合并而成的中尺度对流系统,在发展过程中产生了局地强降水,从而引发了特大泥石流灾害。整个过程中有5个阶段出现了合并现象:首先,多个对流单体合并形成中尺度对流系统;在中尺度对流系统的发展和维持过程中,3个阶段出现了新旧对流系统的合并;在系统即将消散的阶段又出现了两个强中心的合并。合并过程不仅促成中尺度对流系统的生成,使得云体增强发展,而且为对流系统维持补充了能量,使系统生命史延长。另外,在5个阶段的合并过程中,合并机制可以归结为内部动力结构变化和外致碰撞合并两大类。其中,在系统形成阶段,外致碰撞合并是主要机制;而在发展维持阶段,包括气压梯度力、辐合抬升、下沉-上升环流加强等在内的内部动力结构变化影响是发生合并的主要原因。Heavy rainfall occurs abruptly at Zhouqu, Gansu Province from 7 August to 8 August of 2010, cau- sing massive mudslide and brings about huge casualties. As an observational fact, it is clear that a meso- scale convective system, which is produced by several convective cells merging, brings heavy rain in local field and the massive mudslide at Zhouqu. The phenomenon of cumulus merging is analyzed using meteoro- logical satellite data, such as FY-2D/E, NOAA 18 and FY-1D, to find out its impact on heavy rain. As NOAA-18 satellite image shows, there are several cells around the Zhouqu at 0638 UTC 7 August 2010. One and half hours later, cells aremerged and forms a meso-scale system. And the meso-scale sys- tem is still developing in FY-1D satellite image. From FY-2D/E satellite images, there are five stages of cumulus merging in the whole process. First, the meso-scale convective system comes out due to the merging of multi-cells from 0700 UTC to 0800 UTC. And it is the developing and maintaining period of meso-scale convective system. The cumulus merges in 3 stages. First, a developing system merges with several nearby new generation cells at about 0930 UTC. Then a systems merges between a mature new generation system and the old convective system from 1000 UTC to 1030 UTC, the new and old systems merge from 1130 UTC to 1200 UTC. Finally, two centers of cloud with cold cloud top temperature are merged as the dissipating of convective system after 1300 UTC. As the centers have been merged, the system develops again and the cold cloud areas have in- creased. As a result of the merging effect, not only a large and complex convective system is produced and be- comes more intensity, but also the lifetime of convective system is greatly enhanced with more convective energy. On the other hand, the mechanisms of merging in five stages could be classified as change of inner dy- namical structure and collision with outer force. At the building stage of meso-scale convective system, collision with outer force is the main c

关 键 词：卫星云图 中尺度对流系统 对流合并 

分 类 号：P426.5[天文地球—大气科学及气象学]