Bethany Williams, age 12, of Lahoma, Okla., for her question:

WHAT MAKES A WHIRLWIND?

A whirlwind is a circular whirling column of air. A whirlwind is caused by a rising of an overheated layer of air near the ground. Whirlwinds happen most frequently in the deserts where the sun heats the air near the dry ground to a high temperature.

The motion of the air as it rises in a whirlwind can often be seen because it usually carries sand and dust 1,000 feet or more above the earth. Over tropical oceans, some waterspouts form in much the same way as whirlwind. Many harmful waterspouts develop from clouds that bring thunderstorms. Such waterspouts begin to form in the clouds and develop downward.