DK - WOW! The Visual Encyclopedia of Everything

WEATHER Driven by the heat of the Sun, circulating currents of air swirl through the lower atmosphere, creating the winds that carry clouds, rain, and snow from the oceans over the land. Without these weather systems the continents would be barren deserts, where life would be impossible. Sometimes, however, the weather can be so violent that it causes destruction on a terrifying scale.

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PREDICTING WEATHER

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Satellite images like this view of a

hurricane in the Gulf of Mexico can help meteorologists predict

the weather. Forecasters also

gather data on wind, temperature,

air pressure, and other variables,

and feed them into computers

that are programmed with mathematical models of the

atmosphere. The computers use the new data to predict how the

atmosphere may react, and so

produce a weather forecast.

ICE STORMS

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Freezing winter weather is normal in

many regions, but freak conditions

can sometimes cause unusually

destructive ice storms. If moist air is

swept over a very cold region, falling

rain may freeze where it lands to

form thick ice. This can bring down power lines, paralyze rail networks,

and turn roads into death traps.

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HURRICANES

The most devastating weather occurs over tropical oceans, where intense heat creates huge storm clouds that revolve around zones of very low air pressure. Winds spiral into the centre at 300 km/h (185 mph) or more, heaping ocean water into “storm surges” that can drown coastal cities. Hurricanes that form over the Pacific Ocean are called typhoons.

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