THE EFFECT OF LOW LEVEL JET ON THE STABILITY OF GRAVITY WAVES
Sun Shuqing (Institute of Atmospheric Physics, Academia Sinica)
The vertical wind shear in environment is introduced into the equations describing gravity wave and the effect on the instability of gravity waves is discussed. It is shown that the jet stream wind profile is a favourable condition for the unstable development of gravity wave even in the stable stratification. The instability varies with the intensity and the height of jet axis. In the same velocity on the jet axis, the lower the height of axis, the larger the growth rate of amplitude is. Thus, the low level jet seems to be a more favourable environment in producing the unstable waves. These results are compared with the synoptic facts.