时间平均流场对风场振动的优势选择作用

本文根据谐谱展开的水平动量方程，在一定的假设下导出了集时间平均场的涡、散性质于一体的诊断关系式——大气振动频率的优势选择判据，并据此讨论了基本?场的水平不均匀对大气振动的影响。通过这个关系式，利用１９８２年ＥＣＭ?ＷＦ资料对优势频率进行了计算，给出了对流层高、中、低各层的全球分布。?从而指出在实际大气中存在着基本场对某频率上的振动有选择放大作用。

The Influence of the Time Mean Flow on the Formation of Dominant Oscillation of Wind in the Atmosphere

Based on the horizontal mementum equations denoted by Fourier spectra coefficients, a relationtaking account of the vortical and divergent nature of the time mean now is obtained under certain conditions.The relation can be used to diagnose the influence of the non-uniform basic wind field on theformation of dominant oscillations of wind disturbance in the atmosphere.By using the ECMWF dayto day grid data of 1982, the frequency corresponding to the dominant oscillation in the wind field iscomputed from the relation.Thus, the global distributions of the frequencies are given at the lower,middle and upper levels in the troposphere.It is pointed out that there do exist the phenomena that thebasic wind field (time mean) could choose the oscillation with a certain frequency as the duminantoscillation in the atmosphere.