Clouds 101

What is a cloud?

Water you can see

At their simplest, clouds are droplets of liquid water or ice in the atmosphere that you can see. There are many types of clouds that form in various locations all over the world for different reasons. The methods of cloud formation are important for researchers to understand so that they can accurately represent cloud behavior in computer models.

So how can you make a cloud?

Heat the ground

As the sun heats the ground during the day, air close to the ground is warmed, too, causing it to become lighter and rise. The rising air caries water vapor, and as it goes up and up it gets colder and colder. Cold air can't hold as much water vapor and eventually the water condenses out into little droplets--clouds.

A big cloud

Courtesy D'Arcy Norman.