Tornadoes with a Twist
Tornadoes are formed in part when warm air gets trapped beneath cold air. When this warm air finds an opening, it spirals up like an inverted bathtub drain, or vortex. Such movement of warm air through cold air is called a convection current. Because air behaves like a fluid, students can observe convection currents firsthand through an experiment involving water. Provide students with a beaker of hot water and a small amount of colored cold water. Make sure that the temperature difference between the two samples is as great as possible, but be sure to emphasize safety when students are handling very hot water. Have students slowly and carefully add cold water to the hot water using an eyedropper and record their observations. Ask them to write conclusions based on their observations. You may want to explain the following