Lightning: Effects in Thunderstorms

There are many violent forces in nature: such as tornadoes, hurricanes, and volcanoes. Although, most weather-related occurrences can be seen in the magnificent thunderstorm. Thunderstorms are not just seen as one product of nature, because so many things can happen with a thunderstorm. One single thunderstorm can include tornadoes, high winds, hail, rain, and lightning. These are all products of just one thunderstorm. One of these products that a storm creates is lightning. Lightning is also listed as one of the most dangerous and deadliest natural occurrences. Lightning bolts can meet and exceed temperatures of thirty-thousand degrees Celsius, which exceeds the temperature of the surface of the sun by four or five times. Even though lightning is so deadly, it can create beautiful forms and colors as it gives off the greatest light show on earth. Man, as of today, is still trying to learn about this awesome force we know as lightning. Lightning is a very powerful force of nature and it has many different aspects, such as how and why lightning bolts are formed, how lightning produces thunder, and also through the many forms and shapes that lightning bolts produce.

How exactly is a lightning bolt created? Meteorologists are still trying to figure out the exact answer to this question. The sequence of events that gives birth to lightning-whether the familiar flashes of a summer storm or the strange variations on that meteorological staple-remains somewhat of a mystery. Inside a thundercloud warm air rises to the top very fast, and then cools down once it has reached the top. The air then begins to sink and it warms up again as it sinks, and then it rises again. All of this air movement forms convective cells. The transfer of heat causes convective cells by the circulation or movement of the heated air. All of this motion in the cloud causes the top of the cloud to get a positive electric charge and the bottom of the cloud to get a negative electric charge. Scientists are not sure how this happens, but it may be due to collisions between small ice particles as they move up and down inside the cloud building up a static electric charge. Little ice crystals that are positively charged gather up high in the cloud, and negatively charged hailstones fall to the bottom of the cloud. Static electricity becomes very intense from all of this movement and it eventually gets so intense that it causes a spark. The spark that it causes is the start of lightning.

Opposite charges between the cloud and the ground is part of the answer to why lightning flashes. There are many different ways that this little lightning spark may choose to travel, and this will be shown later. Most of the time the spark interacts between the cloud and the ground. Lightning is started when the little spark jumps from the bottom of the cloud, where all of the negative charges are, and goes to the positively charged ground. The path that these negative charges take are called channels and each channel is only an inch or two wide. The energy that is created here, is returned by a flash from the ground, (which can be either from the ground, or a tree, or building), that is positively charged. This flash from the ground moves upward towards the cloud and follows the same path as the other flash. The flashing keeps occurring until the positive charges from the cloud and the negative charges from the ground are neutral again. Lightning is what causes these two different charges to equalize. The brilliant flash occurs when the electrical charge excites the molecules of air in its path, causing them to release light.

All of this disturbed energy is what creates thunder. Thunder is basically a byproduct of lightning. Thunder is the claps and rumbles heard during a thunderstorm. It is the lightning that makes this sound because some of the huge amounts of energy from the lightning flashes are turned over into heat. Lightning heats the air to more than thirty-thousand degrees Celsius. This causes the air in the lightning's path to expand, and the expanding air cools down and contracts. All of this moving causes the air molecules to move back and forth, thus creating sound waves.

When a lightning bolt flashes through the sky, we see it the instant that it occurs, but thunder, the sound that lightning creates, takes a few seconds longer to reach us. On average sound travels about one mile every five seconds. If you start counting seconds as soon as you see the lightning and it takes five seconds until you hear thunder, then the lightning stroke is about one mile away; in ten seconds, it is two miles away. We hear the rumbling as sound from the different sections of a flash hits our ears first. The parts of the flash that is closest to us, is heard first. If lightning struck a mile away, we would hear the section of the flash that hit the ground first, and then the section of the flash that was near the cloud bottom. Many scientific observations can be made about a lightning bolt just by hearing the thunder that it produces. By measuring the travel time, duration, loudness and pitch of thunder claps, peals and rumbles, estimates can be made of the length, orientation, altitude and energy of the leader channel of a lightning bolt. A rumble, opposed to a single clap of thunder, indicates a channel pointing away from the observer. For example; the deeper the rumble, the more energy has been released.

Lightning bolts can travel many different directions, and also create many different effects. The direction that a lightning bolt takes begins at the cloud and advances in steps: the so-called "stepped leader." Not too far from the ground the stepped leader contacts a travelling spark that is sent up by the object that is going to be struck, and produces a "return stroke." It is the return stroke, not the weakly luminous stepped leader, that we actually see. This would make us assume that lightning travels from ground to cloud, not from cloud to ground. In fact it does both. More often than not, lightning flashes inside a cloud or between one cloud or another and it never touches the ground. This is referred to as sheet lightning. Sheet lightning is a white flash that covers a large area of the sky. It is a reflection of a lightning flash that is hidden by the clouds. Another form of lightning is fork lightning. When lightning flashes, the energy moves along the path that has the least resistance. This is very irregular, which is why a flash between the ground is forked or jagged. Another form of lightning is called "bead lightning." This form is very rare. It appears as a series of glowing pearls and dashes. Why this form of lightning is so segmented is yet unknown by scientists. Some believe that this beaded path of a usual downward force of lightning is all an optical illusion. The rarest form of lightning is known as "ball lightning." Ball lightning appears as a spherical light. It hovers or moves slowly a little way from the ground, and then vanishes. Besides unleashing tremendous energy, lightning manifests a range of shapes and colors.

The many different aspects of lightning, such as how and why it is formed, how it produces thunder, and the many shapes and colors it can produce all define the power lightning produces. Lightning can be very destructive, as it holds huge amounts of power and energy. It moves at speeds close to the speed of light and holds temperatures greater than the surface of the sun. Lightning produces sound as its tremendous force disturbs the air, thus producing heat. Lightning has been seen across the world by almost everyone. It can take many forms, shapes, and colors. The most common forms are sheet lightning, and forked lightning. It also produces shapes that are very rare, and almost never caught on film. These forms are known as bead lightning and ball lightning. There is still a lot for scientists to learn about lightning, but until they do lightning will continue to amaze its observers, with its tremendous, natural power.