Rose Begley, age 9. of Taylorsville, Ky:
What causes an electric storm?
The towering white thunderheads pile up in the blue sky like mountains of new fallen snow. In a short while the white becomes pearly grey, then a dark, glowering curtain spreads over the sky. There is war in the heavens, the thunder of guns and the flash of artillery. Then down comes the splashing rain, sometimes mixed with bullets of pelting hail. The turbulent storm, however, is usually only about ten miles wide and it travels only a few miles overhead. It is soon spent, leaving the sky clear again
The energy in a thunderstorm may be equal to 100 million volts of electricity, enough to light a city. The power 3.s ordinary direct current, but so far no one has figured out how to use it. This tremendous energy is generated from vast temperature differences in a sizable column of air reaching from the ground up to five or even 15 miles above our heads.
These weather conditions occur when the air near the surface is warm and the air above is much, much cooler. On a summer’s day, the sun scorches the ground and the ground warms the slim layer of air which touches it. The heat, however, is slow to reach the cool air a few miles above. During a winters night, the sea and the air above it lose their warmth slowly and the higher air chills off fast. Thunderstorms tend to occur over the land on hot summer days and over the ocean during the late winter nights.
The column of warm air below and much cooler air above is called a steep temperature gradient. Moist air, containing plenty of water vapor, also must be available in order for a thunderstorm to form. When these conditions are built up to a critical point, the warm surface air begins to rise in an updraft. Aloft, it comes in contact with the much cooler air and the conflict begins. Turbulent winds sweep up, down and around. Warm currents brush with cool currents, dry air meets damp air.
In the turbulent tangle, particles of air, dust and vapor crash and collide, Countless trillions of the tiny collisions generate the electric batteries of the storm. In the conflict, masses of vapor become chilled and form into raindrops or pellets of hail. Soon the rain begins to fall, cooling the warm, lower air on its way down. The warm, rising updraft turns into a down draft of cool, descending air. Soon the original column of warm and cool air is mixed together, the temperature gradient becomes more stable and the storm dies down.
In the turbulent melee of the storms, countless trillions of colliding air molecules lose electrons. This builds up conflicting charges of positive and negative electricity which are discharged in a flash of lightning. The thunder roars when the flashing of lightning breaks the sound barrier.