|Thunderstorms||Thunder and Lightning|
* The diameter of a lightning bolt is about a half-inch to an inch wide, but can be up to five inches wide. The average length of a lightning bolt from a cloud to the ground is three to four miles long.
* When lightning strikes a sandy beach, the intense heat turns a small portion of the sand into glass. These icicle-shaped pieces are called "fulgurites."
* A flash of lightning appears to flicker because there are usually several bolts of lightning striking at almost the same time.
* Lightning can occur not only in thunderstorms, but also in snowstorms, sand storms, above erupting volcanoes and from nuclear explosions.
Have you ever seen tall, dark puffy clouds
forming on a hot humid afternoon? These are called cumulonimbus clouds, sometimes
nicknamed "thunderheads." They
can actually form any time of day when the temperature falls rapidly higher up in the sky.
These tall dark clouds are full of moisture and contain strong up and down air
currents. Cumulonimbus clouds may tower more
than 50,000 feet, and cover from just a few square miles up to two hundred square miles.
To put it simply, lightning is electricity. It forms in the strong up-and-down air currents inside tall dark cumulonimbus clouds as water droplets, hail, and ice crystals collide with one another. Scientists believe that these collisions build up charges of electricity in a cloud. The positive and negative electrical charges in the cloud separate from one another, the negative charges dropping to the lower part of the cloud and the positive charges staying ins the middle and upper parts. Positive electrical charges also build upon the ground below. When the difference in the charges becomes large enough, a flow of electricity moves from the cloud down to the ground or from one part of the cloud to another, or from one cloud to another cloud. In typical lightning these are down-flowing negative charges, and when the positive charges on the ground leap upward to meet them, the jagged downward path of the negative charges suddenly lights up with a brilliant flash of light. Because of this, our eyes fool us into thinking that the lightning bolt shoots down from the cloud, when in fact the lightning travels up from the ground. In some cases, positive charges come to the ground from severe thunderstorms or from the anvil at the very top of a thunderstorm cloud. The whole process takes less than a millionth of a second.
Kinds of Lightning
There are words to describe different
kinds of lightning. Here are some of them:
Lightning bolts are extremely hot, with temperatures of 30,000 to 50,000 degrees F. That's hotter than the surface of the sun! When the bolt suddenly heats the air around it to such an extreme, the air instantly expands, sending out a vibration or shock wave we hear as an explosion of sound. This is thunder. If you are near the stroke of lightning youll hear thunder as one sharp crack. When lightning is far away, thunder sounds more like a low rumble as the sound waves reflect and echo off hillsides, buildings and trees. Depending on wind direction and temperature, you may hear thunder for up to fifteen or twenty miles. Thunder is only a noise and is nothing to be afraid of. But lightning can be dangerous. Head to the next page to find out how to stay safe from it.
Planning a trip to some stormy areas? Check these out before you go:
ęCopyright 2012 Nick Walker/Small Gate Media