COntents 16-17 El Niño Temperature changes Troublemaker Killing the coral 4-5 WHAT IS WIND What makes wind blow Windsocks Weathervanes Weather balloons 6-7 BREEZE TO GALE Wind speed The Beaufort Scale Measuring wind 8-9 MOVING GASES Oxygen Gases in the air Carbon dioxide 10-11 DESTRUCTIVE WINDS Storms at sea Early warning Wind speed Twisters and waterspouts 12-13 MAKING WAVES Trade winds Currents Wind and tides Crossing the Pacific The Kon-Tiki 14-15 JET STREAMS Westerley winds Flying the jet stream High in the sky 18-19 WIND IN SPACE Aurora Planetary wind Solar wind Comets and meteors 20-21 NAMING THE WIND Wind gods Names of winds Haboobs 22-23 WINDY CLIMATE Wind and weather Air pressure Mapping air pressure Barometers 24-25 WINDSWEPT Desertification Lost Kolmanskop Vanishing hedgerows Great Green Wall of Africa 26-27 WIND EROSION Aeolian processes
28-29 SPREADING SEEDS Seeds in the wind Seeds with wings Pollen in the wind Tumbleweed 30-31 SMELLS IN THE WIND History of smells How perfumes are made Animal scents Bad smells Why things smell 32-33 FARMING WITH WIND Windmills Different windmills Turning sails Salt pans 34-35 DRIED CROPS Winnowing Scarecrows Dried meats Wind-drying fish 36-37 MESSING IN BOATS Dinghies Circumnavigating Yachts Land sailing Windsurfing 38-39 WIND TRAVEL Early seafarers Explorers Tall ships Skysails cargo ships Cutty Sark 40-41 FLYING THE FLAG History of flags National flags ShipZs messages World flags City flags 42-43 FLY A KITE Early kites Kite festivals Fighting kites 44-45 WIND MUSIC Brass Didgeridoo Blow your horn Reed and lips Bagpipes Panpipes and flutes 46-47 BIRDS How birds glide Largest birds Soaring on thermals Bats Bird migration 48-49 ANIMAL WIND SENSE Infrasonic sounds Sharks Wind birds Whales 50-51 HUMAN FLIGHT Leonardo da Vinci Early flying 52-53 IN FLIGHT Getting up Super Airbus Takeoff and landing Gliding 54-55 WIND RESISTANCE Slowing down Speeding up Airflow 56-57 ART IN THE WIND Wind art The Bucket Fountain 58-59 WIND AND POWER Wind and electricity How turbines work Wind farms GLOSSARY and INDEX
4 What is wind A windsock that is filled with strong wind hangs horizontally Wind is another name for moving air Air is a mixture of gases that together make up the atmosphere that surrounds the Earth Our atmosphere contains nitrogen oxygen argon and small amounts of carbon dioxide as well as other gases Air moves all around our planet It can be gentle or forceful Gentle winds can fly a paper kite strong winds can tear down trees What makes wind blOw The Sun heats whatever it touches and when it heats up air the air becomes warmer and lighter Warm air is lighter than cool air so it rises Cool air moves in to replace the warm air This movement of warm air rising and cool air replacing it is what creates breezes winds and even hurricanes WindsOcks Even the most technologically-advanced airports still use windsocks to show the strength and direction of the wind The wind fills the sock and makes it point away from the direction the wind is coming from When the wind is strong the sock will point almost horizontally but it will hang down when there is little or no wind
Weathervanes A weather vane is mounted on a roof or tower and swings round as the wind blows always pointing in the direction itZs blowing It often has a cockerel on the top which is why it is sometimes called a weather-cock Below the cockerel are the four points of the compass They are fixed in place and show where the wind is coming from and blowing to Weather ballOOns Weather balloons are instruments for collecting and measuring information about the air high above the ground They are filled with hydrogen or helium which are both gases that are much lighter than air They can rise about 25 miles above the ground They carry a radio probe that records information on atmospheric pressure temperature humidity and wind speed 5 A traditional weather-cock shows wind direction KEY WORDS gas atmosphere windsock weather vane compass weather balloon wind speed Weather balloons are released twice daily from 800 locations around the globe
