龙卷风的漏斗结构理论  

A THEORY ON THE FUNNEL STRUCTURE OF TORNADO

作　　者：刘式适[1] 付遵涛[1] 刘式达[1] 许焕斌[2] 辛国君[1] 梁福明[1] 

机构地区：[1]北京大学物理学院,暴雨与旱涝灾害教育部重点实验室,北京100871 [2]中国人民解放军总参谋部大气科学研究所,北京100029

出　　处：《地球物理学报》2004年第6期959-963,共5页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目资助 ( 4 0 0 3 5 0 10 );科技部社会公益专项基金项目 ( 2 0 0 2DIB2 0 0 70 )

摘　　要：龙卷风是大气中风速和垂直速度极大的小尺度系统 .本文用气压梯度力、惯性离心力、黏性力三力平衡的柱坐标 (r ,θ,z)下的大气动力和热力学方程组 ,求龙卷风的三维速度场 (vr,vθ,vz) ,从理论上绘制出龙卷风的三维漏斗型结构 .充分说明龙卷风由涡旋流和急流这两种流叠加而成 ,涡旋流是由惯性离心力造成的 ,急流是由水平辐合辐散而引起的强对流 .Tornado is a small-scale system which as the maximal horizontal and vertical velocities in the atmosphere. From the governing equations satisfying the balance between pressure gradient force, inertial centrifugal force and viscous force, the three-dimensional velocities of tornado are obtained, and then its funnel structure is depictured theoretically. It shows that the funnel structure consists of vertex flow and jet flow. The vortex flow is resulted from inertial centrifugal force and the jet flow is from strong convection by the horizontal convergence. At the same time, it indicated that tornado is formed under the exceedingly unstable atmospheric stratification conditions.

关 键 词：龙卷风 漏斗结构 涡旋流 急流 大气科学 

分 类 号：P433[天文地球—大气科学及气象学]