Clouds By Patti Hutchison

Transcription

1 Clouds By Patti Hutchison 1 Bows and flows of angel hair, And ice cream castles in the air, And feather canyons everywhere I've looked at clouds that way. But now they only block the sun, They rain and snow on every one. So many things I could have done, But clouds got in my way. I've looked at clouds from Both sides now, From up and down, And still somehow It's cloud's illusions I recall. I really don't know clouds At all. - from the song "Both Sides Now" by Joni Mitchell 2 Remember when you were little and you and your friends would lie back on the grass and look up at the summer sky? It was fun to see dragons, bunnies, cars, and other shapes in the white, puffy clouds. Sometimes you look out at the gray, cloudy sky on a rainy day and wish the sun would come out. In the late fall, big puffy dark clouds form in the sky. Sometimes people say, "Those look like snow clouds." On a hot, sunny afternoon, suddenly high, dark clouds move in and it begins to storm. Clouds come in many different shapes, sizes, and colors. 3 You usually can't see them, but there are always tiny particles of dust in the air. They might be dirt, pollen, or sea salt. They are called condensation nuclei. The water vapor in the air condenses around these particles. When millions of them collect, a cloud is formed. Not all clouds are alike, however. Clouds form at different heights and in different shapes. There is a classification system for clouds based on these differences.

2 4 Clouds are named by the way they look. Meteorologists use Latin root words to describe them. The most common clouds are puffy white clouds called cumulus. This word in Latin means, "heap." Cumulus clouds are usually seen on a sunny day. They may block the sun for a little while. Usually the breeze blows them away, and the sun comes out again. 5 The root word stratus means layer. Stratus clouds are usually seen on a rainy day. They are like a blanket of light gray in the sky. There are few breaks in them. You can't tell where one cloud ends and another begins. 6 Cirrus clouds are thin and wispy. They look like curly streaks of white in the sky. Cirrus clouds are high in the sky and are made of ice crystals. They occur on a fair day. They point, or curl in the direction the air is moving. 7 The word nimbus is used when a cloud is giving off rain or snow. Nimbus means cloud. They are dark gray and cover the whole sky. They may produce a thunderstorm or even a tornado. 8 Clouds have different prefixes according to their height. A prefix (letters attached to the beginning of a word) is added to show where the cloud formed. The prefix cirro- is used for clouds forming more than 6000 meters above the ground. For example, cirrostratus clouds are high thin clouds that cover the whole sky. They are usually made of ice crystals. Usually you can see the sun through them. Sometimes you can only tell they are there because there is a halo or ring around the sun or moon. 9 Alto is the prefix given to middle level clouds. Their bases are between 2000 meters and 6000 meters. Altocumulus clouds are the small, puffy, white clouds that look like sheep's wool. They are usually seen just before a cold front comes through. Altocumulus clouds that move in on a sunny day are usually followed by a thunderstorm. Stratus clouds can also form at mid level. They are called altostratus clouds. They usually bring light rain or snow. 10 A cloud that forms below 2000 meters is given the prefix strato. They usually contain water droplets. When the air is very cold they may contain snow or ice crystals. Stratocumulus clouds are low, lumpy clouds with small breaks of clear sky in between. They may cause very light precipitation. They usually have shades of dark and light gray. 11 Sometimes Latin root words are combined to describe a certain kind of cloud. Cumulonimbus clouds are also called thunderheads. They are formed when fair weather cumulus clouds grow taller and darker. They are towering dark gray clouds that can produce powerful thunderstorms or even a tornado. 12 If you know the meanings of these Latin root words and prefixes, you can understand how they are combined to name clouds. You can look up at the clouds and know what kind of weather to expect.

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4 Name Date Clouds 1. Puffy white clouds on fair weather days are called: Cumulus Nimbus Stratus 2. Describe a cirrus cloud. 3. You see a blanket of gray clouds in the sky. You can hardly tell where one cloud leaves off and another begins. These are: Stratus clouds Cumulus clouds Nimbus clouds 4. A cloud that forms 6000 meters above the ground would have the prefix: Cirro Alto Strato 5. At what height are altocumulus clouds formed? 6. What kind of weather do nimbostratus clouds cause? Light, steady precipitation Heavy rain or snow Warm, sunny weather

5 1 Cumulus 2 Thin, wispy clouds that point in the direction the air is moving 3 Stratus clouds 4 Cirro to 6000 meters. 6 Light, steady precipitation Clouds - Answer Key