摘要
本文应用一个准二维的非线性非静力数值模式研究了线性和非线性横波型不稳定的中尺度模态的发展、演变和结构特征。结果表明：Ｒｉｃｈａｒｄｓｏｎ数对横波型不稳定的发展和演变有影响。Ｒｉ数越小，不稳定增长越快，且增长率最大的波的波长就越短。非线性横波型不稳定在其发展初期，可以用线性理论作很好的近似；随着不稳定的进一步发展，扰动增强，非线性作用增强，其扰动结构与线性情况相比发生了很大变化，扰动结构最后演变成以顺时针环流为主的结构。
nonlinear and nonhydrostatic twodimensional numerical model is used to study the development,evolution and structure of mesomode transversal instability.The numerical test states that development and evolution of transverse instability are affected by Ri number.The smaller Ri is,the larger its incresing rate and the shorter its wave length with the largest incresing rate is.The initial growing of the transverse instability perturbations can be fairly well approximated by linear theory.With increase of the perturbations,nonlinear interaction of advection term enhances,and its sturctrues has great change,at last clockwise circulations dominate in the disturbance structures.
出处
《气象学报》
CSCD
北大核心
1998年第4期447-457,共11页
Acta Meteorologica Sinica
基金
中国气象局强风暴实验室"飑线的数值试验及理论研究"课题
