Referred to as typhoons in the Pacific, hurricanes in the Atlantic, and tropical cyclones by meteorologists these intensely powerful storms claim more lives each year than any other kind of storm. They can uproot trees, tear houses off of their foundations, and throw cars around like they were toys. It is not unusual for winds to reach 250 mph (360kph)in hurricanes. And their "storm surge" has a 25 feet high wall of water that completely deluges coastal areas. But what role does the Sun have in the development of hurricanes?
During the summer and fall months, the sun's radiation beats down continuously on the ocean waters in the tropics. As a result, warm air rises and drifts upward. Cooler air from the sky takes the place of the rising, warm air. This is known as a convection cycle.
The convection cycle is what it takes to start a storm. The cooler air begins spinning counter clockwise around the developing storm. As the warm air continues to rise in the convection cycle, the atmospheric pressure will fall, making the winds blow stronger. The cycle continues on and on until it either " blows out " or the conditions are right to turn into a hurricane.
Before a hurricane is able to develop, the ocean waters must have a surface temperature of at least 80 degrees F. Air near the ocean surface must have a great deal of moisture. And the winds must be converging which means coming together from different directions.
As a storm system develops, moisture continues to evaporate from the ocean surface. This moisture condenses as it rises. Soon, clouds and rain become caught up in the circular motion of a storm. As long as the tropical storm remains over the warm water of the open ocean, the hurricane can get stronger and larger.
The system is called a tropical depression if the winds of the developing storm remain less than 35 mph. The storm is classified as a tropical storm when the wind speeds reach 35 to 74 mph. Now the storm is given a name so that it can be identified, tracked, and weather forecasts may be made.
When the storm winds reach 75 mph or more, a hurricane is said to be "born". Hurricanes can be as large as 600 miles in diameter, and can reach to heights of 50,000 feet into the sky.
©Copyright 1998 Elizabeth
Beckett, Holly Bernitt, and Vishwa Chandra.