Saturday, May 23, 2015

Why are there clouds?

This video should be a part of every ground school.

The only way to improve it would be to use fewer hot air balloons and more gliders.


Anonymous said...

It does mention one thing which has been argued over: when the condensation in the cloud generates some more heat, does the cloud then "suck" more air from below? How?

T8 said...

The latent heat of condensation results in a different adiabatic lapse rate for saturated air. This is easily displayed on a skew T. Absent an inversion which caps convection and given a moist airmass, what happens is that the bouyancy of the rising parcel increases once condensation begins and so the ascent rate of the lifting parcel may increase. The "cloud suck" phenomenon is the wake of the ascending cloud. It is a real effect.