Abstract
In this article we will discu s s, by the use of the linearized form of equations of motion, how the forced perturbations created by large mountain barriers change their shape with increasing height. It is found that (1) the amplitude of the forced perturbations is largest at the level s=-1/2 (corresponding to the 250-mb isobaric level), where we usually encounter the jet stream, (2) even in the stratosphere where the static stability is extremely large, we still find pronounced forced perturbations with characteristic wave number 2, suggesting that the very long waves are able to penetrate significantly into the stratosphere.