Influences of Richardson Number on the Instability of Meso-α Scale Vortex Wave
Zhang Lifeng, Wang Liqiong and Zhang Ming(Institute of Meteorology, PLA University of Science and Technology, Nanjing 211101)
The influences of Richardson number Ri on the instability of meso-α scale vortex wave is discussed. The results are as follows. There is close relationship between Ri and the destabilization of meso-a scale vortex wave. The instability of meso-α scale vortex wave appears only when Ri is not large. The smaller Ri is, the easier the appearance of heterotropic instability is and the shorter it's wavelength is, temporality the heterotropic instability is ascendent in meso-a scale waveband. The condition of weak stable stratification is advantageous to instability of meso-a scale vortex wave, but the augment of wind shear is only advantageous to the increase of the unstable growth rate.