WIND SCIENCE SECRETS Jason Cooper
www.rourkepublishing.com
© 2003 Rourke Publishing LLC All rights reserved. No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical including photocopying, recording, or by any information storage and retrieval system without permission in writing from the publisher. www.rourkepublishing.com PHOTO CREDITS: Cover, pages 2, 17, 21 © Painet, Inc.; Title page, pages 4, 8 © Corbis Images; pages 10, 18 © Photodisc, Inc.; pages 12, 13, 15 Title page: Wind pushes along this windsurfer. Series Editor: Henry Rasof Cover and interior design by Nicola Stratford
Library of Congress Cataloging-in-Publication Data
Cooper, Jason, 1942Wind / Jason Cooper. v. cm. — (Science secrets) Includes bibliographical references and index. Contents: Unseen wind -- What makes the wind? — Trade winds — Wind energy — Windmills — Measuring the wind — Hurricanes — Tornadoes — More wind storms. ISBN 1-58952-415-2 1. Winds—Juvenile literature. [1. Winds.] I. Title. II. Series: Cooper, Jason, d 1942- . Science secrets. QC931.4 .C66 2002 551.51'8—dc21 2002015738 Printed in the USA
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TABLE OF CONTENTS Unseen Wind What Makes the Wind? Trade Winds Wind Energy Windmills Measuring the Wind Hurricanes Tornadoes More Wind Storms Glossary Index Further Reading/Websites to Visit
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UNSEEN WIND Whoosh! Wind is just a motion, a movement of air. We cannot see it. But we can feel its force. And sometimes we can see what it does. Sometimes the wind almost seems to speak, with a soft whisper or a noisy howl.
The blowing wind can create large waves.
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WHAT MAKES THE WIND? Air is the substance we breathe. Air covers the earth’s surface. It has no taste and no smell. Air can be dry or wet, hot or cold. You can think of each kind of air as a different type of bubble. The movement of these bubbles helps make wind. The earth spinning in space also helps the air to move.
Wind affects clouds on Planet Earth.
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TRADE WINDS In some places in the world, the wind almost always blows. And it usually blows from the same direction. Some steady winds that blow over oceans are known as trade winds. They used to help sailing ships cross the seas. These sailing ships carried people and goods from one part of the world to another.
Trade winds still help modern sailing ships.
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WIND ENERGY Wind seems to come and go as it pleases. And the wind is full of energy. The wind’s energy is a powerful force. Sometimes we can harness the wind’s energy, or power, to help us.
Giant windmills use the wind’s energy to produce electric power.
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Some plants rely on the wind to spread their seeds.
Wind energy helps lift this pelican.
WINDMILLS Windmills capture the wind’s energy. They are made in many sizes and styles. But all of them have sails or paddles that the wind pushes. As the wind pushes the sails, the parts of the windmill move. The windmill can then pump water, for instance. Or the windmill powers a machine that makes electricity.
An old-fashioned windmill
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MEASURING THE WIND A weather vane turns in the wind and can show the wind’s direction. The wind can blow from the east, west, north, or south. An anemometer measures the speed of the wind. The wind may blow from one direction at ground level. It may blow from another direction higher up. The wind may also blow at different speeds at different heights.
An anemometer measures wind speed.
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HURRICANES A hurricane is a powerful, wet storm that begins over the ocean. Most hurricanes in the United States begin in the Atlantic Ocean. And most begin in August or September. The U.S. Weather Service gives names to all hurricanes. To be called a hurricane, a storm must have winds of at least 74 miles (120 kilometers) an hour. A hurricane may be as much as 450 miles (720 km) across. It can last several weeks before striking land. The storm tends to die down in force when it hits land, although it can still do terrible damage. The eye of a hurricane appears as a small hole near the center of the storm. There the air remains calm.
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TORNADOES A tornado is a violent, whirling wind storm that begins in thunderclouds. It can be seen as a cloud shaped like a funnel as it heads toward the ground. A tornado usually lasts a very short time. The wind speed of a tornado can reach over 300 miles (500 km) per hour. A tornado striking the ground destroys almost everything in its path. Tornadoes that form over water are known as waterspouts. A tornado gets its color from the dirt and debris it picks up from the ground.
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MORE WIND STORMS Tropical depressions are storms that are weaker than hurricanes. They occur mostly in very warm areas. Winds that blow during snowstorms often cause blizzards. People can’t see very far ahead of them, which makes traveling difficult. Winds in the deserts create storms that stir up sand and dirt. These storms can quickly make the day as dark as night. Wind is an incredible force of nature.
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GLOSSARY anemometer (an eh MOM eh tur) — an instrument that shows and measures wind speed blizzards (BLIZZ urdz) — blinding snowstorms harness (HAHR nuss) — to channel, or focus hurricane (HER uh kane) — a powerful wind storm with a wind speed of 75 miles (120 km) an hour tornado (tohr NAY doh) — a powerful windstorm with a small center that can cause a lot of damage trade winds (TRAYD WIHNDZ) — a group of steady winds that blow from east to west along one path and from west to east along another tropical depressions (TRAPH uh kul de PRESH unz) — strong rain and wind storms, but with winds that don’t come up to hurricane force waterspouts (WAH ter spowtz) — tornadoes over large bodies of water weather vane (WEH thur VAYNE) — a device used to tell wind direction
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Index air 6 anemometer 16 Atlantic Ocean 19 blizzards 22 electricity 14 energy 11, 14 hurricanes 19
thunderclouds 20 tornadoes 20 trade winds 9 tropical depressions waterspouts 20 weather vane 16 windmills 14
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Further Reading Burby, Liza. Tornadoes. New York: Rosen, 1999. Fowler, Allan. Can You See the Wind? Danbury, CT: Children’s Press, 1999. Hiscock, Bruce. The Big Storm. New York: Atheneum, 1993.
Websites To Visit www.sci.mus.mn.us/sln/vollis/ www.nws.noaa.gov/om/reachout/kidspage.shtml www.energyquest.ca.gov/story/chapter16.html .
About The Author Jason Cooper has written several children’s book series about a variety of topics for Rourke Publishing, including Eye to Eye with Big Cats and Money Power. Cooper travels widely to gather information for his books.
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