华北平原一次中尺度对流系统分析  

Analysis on A Mesoscale Convective System in North China Plain

作　　者：吕胜辉 高艳红[2] 刘伟 

机构地区：[1]中国民航天津空中交通管理站,天津300300 [2]中国科学院寒区旱区环境与工程研究所,甘肃兰州730000 [3]民航兰州空管中心,甘肃兰州730087

出　　处：《高原气象》2005年第2期268-274,共7页Plateau Meteorology

基　　金：中国科学院寒区旱区环境与工程研究所创新课题(2004109)资助

摘　　要：2002年6月1日在华北平原发生了β尺度的中尺度对流系统(MβCSs)。利用气象常规资料的客观分析产品对这次过程进行了分析, 结果表明, 在高空东北冷涡影响下, 华北平原的东北方向出现急流, MβCSs发生在急流右侧的风速切变区中; 由于高空正涡度平流、低空负涡度平流的共同作用,高空辐散, 低空辐合, 使对流层中层的上升运动得以维持; 华北平原低空水汽通量辐合,有源源不断的水汽供应; 高层总能量减少, 低层总能量增加, 使华北平原在垂直方向有大量的不稳定能量积聚。以上分析表明: 华北平原具备了对流产生的动力和热力条件。该文揭示了MβCSs产生的原因, 并为以后进一步做好MβCSs的预报总结了经验。Meteorological routine observation data are used to analyze a Mesoscale Convective System (MβCSs) on the Meso-β scale which takes place in the North China Plain on June 1, 2002. The results show that the convective system occurs in the wind shear zone, and it locates on the right-hand side of upper-level jet stream, and which exists in the northeast part of North China Plain, due to the influence of the Northeast Cold Vortex. The collective effect of upper-level positive vorticity advection and low-level negative vorticity advection results in both upper-level convergence and low-level divergence, which tend to maintain the ascending motion of middle troposphere in this region. Low-level moisture flux convergence provide plenty of water vapor. Then decreasing(increasing) the total energy of the upper(low)-level airso that a large amount of unstable energy develops over the North China Plain. This circulation pattern favors convective systems and finally triggers the mesoscale convective system. This paper sheds light on the causes of MβCSsand provides some experiences for forecasting MβCSsin the future.

关 键 词：中尺度对流系统 对流稳定度 涡度平流 温度平流 总能量 

分 类 号：P445[天文地球—大气科学及气象学]