Johnny Graves, age 10, of Marysville, N.B., Canada, for his question:
DO THEY KNOW HOW HURRICANES FORM?
The parents of a howling hurricane are the beaming sun and the spinning earth. It is born above tropical seas, where the warm air becomes loaded with moisture. There are only a few suitable places where this can happen. But when those huge wild storms are ready, they move out from their hurricane hatcheries and travel hundreds of miles.
A hurricane may start to form when the hot sun beams down on a vast ocean for days and days. All is calm as the warmth evaporates moisture and more moisture from the surface of the sea. The likely place is in the tropics, either just north or just south of the equator. During this calm period, the warm air near the surface expands and, as it needs more room, it rises aloft.
In time, it forms a strong current of light, rising air, surrounded by heavier, somewhat cooler air on all sides. It is natural for masses of cooler, heavier air to flow and blow into masses of light, warm air. So, after the calm spell, breezes from all sides start to blow toward the center where all the air is wafted aloft.
The winds blowing inward are heavy with cloudy moisture. The rising central current is calm and cloudless. Soon the spinning earth causes the inflowing winds to swerve toward the right. That is, if the hurricane is born north of the equator. If it hatches in the Southern Hemisphere, its winds swerve to the left. In any case, the hatching hurricane becomes a great doughnut of winds, spiraling into the calm central eye of the storm.
Meantime, in the tropics the ceaseless trade winds blow westward around the globe. Soon they capture the stormy pocket of spiraling winds and whisk it along toward the west. As it goes, the furious storm mixes and mingles vast masses of air damp and dry, cool and warm. It draws in moisture and energy from afar. But at last it wears itself out. Somewhere, miles from home, over land or sea, the wild winds die down and the skies clear.
Hurricanes that sweep over eastern North America are hatched above the warm seas around the West Indies. The easterly trade winds often carry them toward our southern shores. There they may swerve northward and tear over the land, perhaps for hundreds of miles. But at last, after terrible damage, they run out of energy and die down. Meantime the next hurricane may be forming around the West Indies.