Cavity resonance is interesting. I originally picked up JoeP's text because I was fascinated by standing wave patterns evidenced by "mackerel sky" clouds (cirrocumulus) high in troposphere. The idea of having a stratification or layer in atmosphere bounded above and below sufficient to trap such waves and cause localized condensations is/was amazing to me. I figured I had no intuition for what was going on. My knowledge of all this is still quite weak.