Virginia Ternes, age 13, of Wichita, Kan
What causes a hurricane?
The changeable weather takes place in the troposphere, the lowest layer of air which reaches from five to 11 miles above the earth. This is a huge volume of air to study and meteorologists from many nations have been comparing notes for years to form a global picture of the weather and its causes. Weathermen can forecast the skies for the next few days, explain the monsoons, the trade winds and other weather events. But there is still much they do not know.
From June to November, our meteorologists watch for the birth of hurricanes around the West Indies. Others watch the Indian Ocean and the waters off western Mexico. During the rest of the year, meteorologists watch for these howling storms to hatch off northern off Australia,/the east coast of Africa and in the southern Pacific. For hurricanes form during certain seasons and in certain places.
The weather conditions necessary to start a hurricane must be just right and spread over a vast area. There must be plenty of moisture, which is why hurricanes hatch over the ocean. There must be heat from days of tropical sunshine, which is why hurricanes hatch during the summer season as it moves north and south of the equator. Another necessary factor is the spinning of the earth which gives a twist to the winds and sets the great spiraling storm in motion. This spin is not felt at the equator, which is why hurricanes hatch just north and south, but never exactly on the equator.
The nesting grounds of the world's hurricanes are in the belts of the trade winds which blow towards the equator from the northeast and from the southeast.
The raging storms often form where contrasting trade winds converge and come into conflict, swirling around each other in a spiraling eddy. North of the equator, the swirl is twisted to the right by the spinning motion of the earth. A hurricane south of the equator spirals in the opposite direction.
The trades, as a rule, are steady winds, but sometimes they blow stronger or die down. A variation builds up a wave or ripple in the prevailing winds which is closely watched by the meteorologists, for this weather event also may start the swirling storm which will become a hurricane. Strong winds, vast masses of warm, moist air over the ocean, and the spinning earth are all factors in the birth of a hurricane. There are other factors we do not know and every hurricane is studied in detail. Maybe someday the meteorologists will solve the final secret and learn how to control these raging storms.
As of now, the weathermen can watch only the birth of a hurricane, predict its path and give warning. As it develops, the huge circular storm is swept along by the prevailing winds over the ocean. Sometimes a land mass will force it to turn its path and many hurricanes from the West Indies turn north off the coast of Florida and sweep harmlessly out to sea.