3. Stability

Changing Stability » Vertical Motion Vertical Motion of a Layer

Photo of wave cloud at sunset

The vertical motions that affect the lapse rate may be of any scale or type, from small-scale turbulence to the large-scale mean vertical-motion field associated with synoptic features. As different principles apply to the vertical motion of different scales or types, we customarily consider the vertical motions of different scales as somewhat distinct phenomena. Accordingly, we will discuss separately ascent and subsidence of whole layers and penetrative convection. The lifting effects of mountains and fronts involve combinations of these phenomena.