晴空湍流（CAT）对大尺度和中尺度动力强迫过程的响应

THE RESPONSE OF CLEAR-AIR TURBULENCE TO MESO-AND SYNOPTIC-SCALE DYNAMIC FORCING PROCESSES

该文利用中尺度客观分析资料，对θ坐标系下Ｒｉ数倾向方程中的非湍流变形强迫场进行了诊断分析，以揭示晴空湍流（ＣＡＴ）对大尺度和中尺度动力强迫过程的响应关系．计算结果表明：晴空湍流往往出现在对流层高层或高空急流附近．在层结稳定的高层大气薄层中，Ｒｉ数较小的空气微团遇有较强的非湍流变形强迫场时，由于动力强迫和Ｒｉ的耦合作用，往往导致晴空湍流的发生．

By using the meso-scale objective analysis data, the forcing field of the nonturbulent deformation in Richardson number tendency equation of θ coordinates is diagnosed in order to study the response relation between clear-air turbulence (CAT) and synoptic-scale and meso-scale dynamic forcing processes.The calculating results show that CAT is often encountered in the upper troposphere ornear upper air jet flows. In the stable shallow layer of upper atmosphere, when micro air mass with small Ri number encounters the strong forcing field of nonturbulent deformation,because of the coupling function of dynamic forcing with Ri number , CAT would incur frequently.