CLOUDS

High clouds ...Cirrus clouds are ice clouds. They can look like delicate white feathers or streamers. They are always more than five kilometres up where the temperature is below freezing, even in summer. Wind currents twist and spread the ice crystals into wispy strands.

Contrails are made by high-flying jet airplanes. They are still clouds, though, because they are made of water droplets condensed from the water vapor in the exhaust of the jet engines.

Mid-level Clouds ...Cumulus clouds are the fluffy, white cotton ball or cauliflower-looking clouds with sharp outlines. They are "fair weather clouds" and they are fun to watch as they grow and change in shape and size..

Cumulus clouds make beautiful sunsets

Cumulonimbus cloudsare a sure sign of bad weather to come—at least bad if you don't like rain and hail!

These clouds grow on hot days when warm, wet air rises very high into the sky. Up and down winds within the cloud may push water droplets up to very cold parts of the atmosphere, where they freeze.

When the ice drops come back down, they get another coating of water and are pushed back up to freeze again. Finally, they get too heavy to stay in the cloud and fall to the Earth as hail stones.

Altocumulus clouds

have white or gray patches or layers, and seem to be made up of round shapes. They are lower than cirrus clouds, but still quite high. They are made of liquid water, but seldom make rain.

Low-level Clouds ...Stratus clouds often look like thin, white sheets covering the whole sky. Since they are so thin, they seldom produce much rain or snow. Sometimes, in the mountains or hills, these clouds appear to be fog.

Special Clouds ... Mammatus clouds are actually altocumulus, cirrus, cumulonimbus, or other types of clouds that have these pouch-like shapes hanging out of the bottom.

Orographic clouds get their shape from mountains or hills that force the air to move over or around them.

Lenticular clouds are shaped like lenses or almonds or...flying saucers! They may get their shape from hilly terrain (another type of orographic cloud) or just the way the air is rising over flat terrain.

Clouds are the sky's way of moving water from one place to another.

Water on land or in the ocean evaporates, turning from a liquid to a gas called water vapor.

The water vapor rises, cools, and then turns back into a liquid, forming tiny droplets. Enough of these droplets make a cloud.

When the droplets come together, they combine to form bigger droplets. When they get big enough, they fall to the ground as rain.

Or, if it's very cold, they freeze and come down as snow or sleet or hail.

Meanwhile, the wind may have blown the cloud a long distance from where its water started.

You can tell a lot from a cloud's shape, size, and "texture."

We put clouds into categories based on their shape, how high they are in the sky, how big they are, how they formed, how fast and in what direction they're moving . . . and so on.

Sometimes clouds are very unruly. They appear to be a little of this and a little of that.

Besides moving water around from one place to another, clouds play a very important part in maintaining Earth's temperature. Scientists need to understand better how clouds affect climate.

Enrichment Activity : Cloudy WeatherStep #1: Cloud in a Bottle

Divide into groups of five - six and collect the softdrink bottle, hot water, and the ice cubes. Pour the hot water into the bottle and screw the cap on tightly. 

Answer the following questions

What is happening to the air in the bottle?

  How could you use the ice cube to cool the air in the bottle?

What do you think will happen when you open the bottle and put an ice cube at the mouth of the bottle?

After 2 or 3 minutes, remove the cap and put an ice cube over the mouth of the bottle.  There should be a cloud just below the ice cube.

What happened? Describe your observations.

  What happens to the air filled with water vapor when it is cooled?

   What two things must be present for a cloud to form?

Step #2: Cloud Observation What do you know about clouds?

Do all clouds bring rain?  

What kind of clouds do you see on sunny days?

 

Have you ever seen clouds that look like feathers, animals, cotton balls, etc.? What was weirdest cloud shape you've ever seen?

Look outside and draw at least one cloud that you see in your books. 

Write as many words as you can to describe your cloud.