Intra Cloud Lightning example essay topic

WEATHER There are many different forms of weather on planet Earth. Some that ac cur day-to-day and others tax ac cur on a more rare basis. Weather is a very broad topic but can be broken down. In my composition, I will explain three types of weather: Lightning, Ice Storms, and Hurricanes. The res on I chose these three topics is to inform people about the different types of weather. Some of it we may already know.

But there are others that we know nothing about. Lightning has been feared as an atmospheric flash of supernatural origin. The Greeks marveled and feared lightning as it was hurled by Zeus. For the Vikings, lightning was produced by Thor as his hammer struck an anvil while riding his chariot across the clouds. In the East, early statues of Buddha show him carrying a thunderbolt with arrows at each end. Indian tribes in North America believed that lightning was due to the flashing feathers of a mystical bird whose flapping wings produced the sound of thunder.

Today we use a more scientific approach to explain lightning. Lightning is a visible electrical discharge that results from the buildup of positive and negative charges within a thunderstorm. When the buildup is strong enough, lightning appears. This discharge produces a series of brilliant flashes inside clouds, between the clouds, and between the clouds and the ground.

The average time interval between each stroke is approximately 0.02 seconds. Each stroke lasts, on average, 0.25 seconds. It is estimated that there are 2,000 thunderstorms occurring on earth at all times. This results in 100 lightning strikes occurring around the world every second, totaling 8.6 million strikes per day and over three billion each year.

Lightning originates in a thunderstorm cloud where charged particles are separated. There are several theories explaining how they separate, but no one really knows what pulls the charges apart. It is believed that water drops in the cloud become negatively charged and, being heavier, fall to the bottom of the cloud. The positive charges are then swept up to the top of the cloud by the warm updrafts in the thunderhead.

As more charges separate, parts of the cloud become so highly charged that the electrical forces tear nearby air molecules apart, making more charged fragments. There are also many types of lightning. Cloud-to-ground lightning is the most damaging and dangerous form of lightning. Although it is not the most common type, representing only 20% of all lightning strikes, it is the one which is most understood.

Most flashes originate near the lower negative charge center and deliver negative charge to the Earth. Some suggest that cloud-to-ground lightning strikes occur most at higher latitudes. Others suggest that cloud top height is a more important variable than latitude. Forked lightning is composed of crooked or branched channels. These bolts may discharge from a cloud to the ground, to another cloud, or out of the top or sides of a storm. Intra-cloud lightning is the most common form of lightning, accounting for 60% of all lightning.

This occurs when opposite electrical charges in one cloud attract those in another. The formation of intra-cloud lightning takes place inside clouds and looks like a bright flash which flickers, to the observer. A flash may leave the cloud. When this occurs, it resembles the cloud-to-ground lightning bolt.

Storms with the greatest vertical development most often produce intra-cloud lightning. Sheet lightning occurs when the lightning is obscured by clouds. The flashes illuminate the entire cloud, making it visible from miles away. With sheet lightning, the observer is near enough to hear the thunder. Heat lightning is very similar to sheet lightning, except the lightning is too far away for the observer to hear the thunder. The flashes are created by lightning bolts occurring in thunderstorms more than ten miles away.

It is called heat lightning because it most often occurs during the summer, at night. St. Elmo's Fire is described as a greenish or bluish glow above pointed objects on the ground. This form of lightning is created by the soft glow of an electric field generated by a continuous flow of sparks. These tiny sparks are positive charges reaching skyward in response to a growing area of negative charge in clouds or air above. It was once thought to protect ships from lightning damage.

However, if a thunderstorm is nearby, St. Elmo's Fire might precede a lightning strike. And finally, ball lightning is an extremely rare phenomenon. It is so rare, scientists often question its existence. Ball lightning is described as luminous balls coming from violent thunderstorms containing a lot of lightning.

They are approximately four to eight inches in diameter and last less than five seconds. Ball lightning is sometimes accompanied by a crackling sound and a sulfurous smell. These incidents are reported to be attracted to metallic objects such as wire fences or telephone poles. Ball lightning does not usually cause damage, but it has been reported to burn through screens and windows. Ice storms are a very intricate type of weather.

It needs certain things to happen and the ice / snow has many forms. An ice storm is usually used to describe occasions when damaging accumulations of ice are expected during freezing rain situations. These accumulations of ice make walking and driving very dangerous. A great amount of ice accumulation are accumulations of 1/4 inch or greater. A situation that occurs once in a while is freezing rain. This occurs when rain or drizzle falls on surfaces (such as the ground, trees, power lines, motor vehicles, streets, highways, etc.) that have a temperature of 32 o F or below making the water droplets to freeze on contact.

Freezing rain is precipitation, but certain conditions have to be met to make moisture from the sky, and have the moisture fall in the form of freezing rain. First, particles of moisture are present in all clouds, but that doesn't result in any form of precipitation until the particles become too large (and heavy), and rain or another type of precipitation is the result. Freezing rain is a specific type of precipitation, as is rain, drizzle, sleet, and hail. Before the rain hits the ground, it goes through a cold layer of air just before the surface of the ground. The drops are cooled, forming supercooled drops, drops that are cooled to below freezing but are not frozen.

When these supercooled drops hit the ground, they thin out and freeze, instantly, forming a thin film of ice. Sleet forms along with ice storms. Sleet forms as a result of snow melting and then refreezes before hitting the ground. It has small pellets of ice that bounce and make tapping sounds when they hit the ground. The ice pellets are see through, round formations of ice. The interior of the pellet can be partially liquid and therefore might break upon hitting a hard surface.

Sleet forms inside a cloud that is above-freezing and in a layer of below freezing air. The cloud will then rain to ground. If the distance from the ground is great enough the rain will freeze and form sleet. A hurricane is a synoptic scale low-pressure system, not associated with a front, that occurs in the tropics and has maximum sustained surface winds, near the center of the storm, of 74 mph or greater. In order to be classified as a hurricane, the storm must have a circular wind flow. Hurricanes are whirling storms, often measuring 200-300 miles across.

These storms often develop (60% of the time) from Eastern waves that move off the coast of Africa and get transported across the tropical Atlantic Ocean by the trade winds. In different parts of the world, these storms are called typhoons, tropical cyclones, severe tropical cyclones, and severe cyclonic storms. When first recognized, the storm has maximum sustained winds below 39 mph and is called a tropical depression. When the winds become sustained at more than 39 mph, but below 74 mph, the system is called a tropical storm, and is given an official name by the National Hurricane Center.

Finally, when the winds reach maximum sustained levels of 74 mph, the storm has reached hurricane status. There are several environmental factors that must be present if systems are to undergo tropical. First, and most importantly, the storm must begin its formation over a body of water that's temperature is at least 80 oF, since it is the evaporation of this warm water that provides the energy for the storm. The atmosphere must be relatively cool in the upper levels, so that the warm evaporated air can rise and form thunderstorms.

If the warm, moist air cannot rise, the energy (in the form of heat) in this air cannot be used for the development of the tropical cyclone. Also, the middle layers of the atmosphere must be somewhat moist, again so that thunderstorms may develop. If these levels are dry, so much moisture is needed to saturate the air that the thunderstorms associated with the storm cannot develop. In order for the storm to maintain its circular flow, the storm must start at least 300 miles from the equator.

A weak low-pressure system is needed. Finally, there can be very little vertical wind shear, or change of wind with height, or else what is needed for thunderstorm development will be disrupted. Even if all these conditions are met, tropical may not occur. However, if these conditions are not met, no tropical cyclones will generate in the area. We should also be aware as to preparing for Hurricanes. The time to begin getting ready for the hurricane season is not when the Weather Channel begins monitoring a developing storm in the Atlantic.

Rather, it is never to early to begin preparing for the coming hurricane season because the are so many things that need to accounted for, including the house, evacuation routes, and emergency kits. It is also important to keep informed on conditions in the Gulf of Mexico, the Caribbean Sea, and the Atlantic Ocean. There are many different forms of weather on planet Earth.