MAKE A THUNDERSTORM
Materials:
Index Cards
Colored Pencils
Ice Tray
Blue Food Coloring
Red Food Coloring
Water
Clear Plastic Container (approx. shoebox size)
Procedure:
1) Fill Ice Cube Tray with water from sink
and put one drop of blue food coloring in each cube hole (making
each cube blue). Place in freezer until water becomes ice.
2) Fill the container 2/3 full with water (room temperature).
3) Place a blue ice cube at one end of the plastic container.
4) Carefully add two drops of red food coloring to the water at the opposite end of the plastic container not disturbing the water.
5) Watch where the red and blue food coloring goes.
6) Using the red and blue pencils draw what you see happening on the index cards.
What's Going on??
You've probably heard that warm air rises. The same theory applies here as the cold water sinks while the warm water rises. This is an example of convection . In meteorology, convection usually refers to motions in the atmosphere that are mainly vertical, such as rising air currents due to surface heating. You can figure that the blue water represents a cold air mass and the red water represents a warm, unstable air mass. A thunderstorm is caused by unstable air and convection plays an important part. As a cold front approaches, a body of warm air is forced to rise. A strong, persistent updraft of warm moist air is formed and lifted by the approaching cold front. Speeds in an updraft can reach 90 miles per hour. The air cools as it rises, condenses, and forms cumulus clouds. When condensation occurs, heat and released and this helps the thunderstorm grow. Sooner or later, condensation high in the cloud falls to the ground as rain.