Sunday, 5 May 2013
I'm all for interesting prints and photos to go on clothes, and I think clouds are really pretty. Not only are there numerous shapes, but also the way the light catches them, and the time of day, make for some stunning illumination and colour.
The science of clouds, their different shapes and heights and classification, would take decades to go over, so I am going to be realistic and simply attempt a general explanation of how clouds form.
Aerosols are tiny particles in the air that water vapour collides with. In some collisions, the water adheres to the aerosol to form a water droplet that makes up a cloud. The cohesion between water molecules that I talked about in the cohesion-tension theory holds the drops together.
This happens when the air is saturated - it can't hold any more water. To saturate the air, you can either increase the concentration of water vapour, or reduce the dew point, the temperature at which the air becomes saturated. The warmer the air is, the more water vapour it can hold, so if you lower the temperature, it can't hold as much water vapour, resulting in condensation.
Below's a handy guide to cloud-spotting. Thanks, Met Office!