Vertical exchange of momentum
The vertical exchange of momentum is a technical term in meteorology . Are mountains or forest edges etc. of vertically propagating waves overflowed , then the corresponding tend phase lines in the opposite direction. This triggers a vertical downward impulse. In unstable air layers this can lead to dynamic gusts with sometimes dangerous wind speeds , if the vertical exchange of momentum with higher air layers , in which higher mean wind speeds prevail, occurs and intensifies this effect. The gusty wind actually observed usually results from a combination of several effects.