Lightning

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Lightning

Introduction

While there are several hypotheses posited to describe and explain the causes of lightning, the scientific description and explanation tend to hold. Munoz, (2003), explains that most fulminologists argue that it is a form of electrostatic discharge in the atmosphere, which usually accompanies thunder. Most of the lightning does occur during thunderstorms or volcanic eruptions.

Formation

As water evaporates from the earth’s surface in form of hot gas through convection into the atmosphere, they replace the cold air and condense beside the clouds to form dark cumulus nimbus clouds. These clouds form approximately 230, 000 feet ASL (above the sea level). As condensed air, forms water droplet while the rest changes into the ice sheet or snow particles. When these ice crystal and the water droplets collide with each other countercurrent, they create static electricity. The static electricity so formed builds up in different parts of the media (cloud and earth). As they build up, they reach various charge potentials. However, if the charge potentials (both positive and negative) reach their thresholds, the clouds discharge them. The positive (ve) and negative(-ve) charges created rapidly in different media tend to attract, however, as they continue to build up, a bridge is created naturally or through other media, a human being or electric poles (Wang, Ushio, & Kawasaki, 1995).

The difference in the electric potential of different part of the cloud causes a rift in which the clouds use a third media (an electric path) to bridge them to facilitate the flow of electric current and th surge results into a main stroke (Munoz, 2003).

How lightning works

Whenever the lower section of the cloud with the negative charges attain threshold, the electric charges within then cloud ionizes the air around the cloud. This turns the surrounding air into an electric path due to the conductivity of the static charges. This builds up and surge travels down to the ground into buildings and infrastructures. As the discharge continues, it creates charge vacuum after the leader stroke. The negative charges tend to move from the cloud to the ground and meets the streamers moving in the opposite direction. This counter movement of the electric charges is defined as the return stroke, which is usually observable to the bare eye. The main strokes lead to the formation of a zigzagging form of the flashes those lights up the airspace following the pathway of the negative charges. The zigzag formation is due to the disparity between the ionization of the air. The most ionized parts appear in the form of sparks of light, and the less ionized parts do not show any lightning

Key characteristics of lightning

A flash of lightning can composes:

Flashes that appear intra-cloud (within the thunder cloud)

The temperatures of the lightning vary between 100 °C to 30,000 °C.

The most noteworthy characteristics are the speed at which lightning travels. The speed ranges from 100, 000km/h to 200, 000km/h.

All these characteristics have both negative and positive effects on nature, but it is common place to notice the negative impacts more than the benefits to nature. The most noteworthy impact is the damage to properties and injuries that people sustain when lightning strikes. However, it may be to fatal to results into death depending on the intensity and magnitude of the lightning.

Figure SEQ Figure * ARABIC 1: picture of the lightning phenomena What causes lightning?

According to Rakov, &, Uman, (2003), there are many causes of lightning, but the most probable explanation bases on the scientific facts around lightning. Wang, Ushio, & Kawasaki, (1995), argue that lightning is appearing during thunderstorms, because liquid and ice particles come into constant collision and as they collide, a large electrical field is developed amongst the clouds. As the electric fields enlarge, they form flashes due to the opposing positive and negative ions. This static electricity discharge is manifested in the form of flashes. This flashes carry with them electric energy being discharged and have an inherent nature of shifting into anything they meet. If the flashes are exposed to a human being and the magnitude of the electric charges within the flashes was high, the damage might be fatal or even kill. However, building is the most hit due to the large surface areas. Lighting effects are often seen in towns with various demographic characteristics, such as Texas.

Types of lightning flashes

There are various types of lightning flashes; this categorization is based on the Nature of occurrences. However, the main types are:

Ground to cloud:

These types of lightning occur due to the difference in electronic charge potential between the ground and the cloud above it.

Cloud to ground-

Cloud to ground lightning occurs when the charge difference between the cumulonimbus clouds and the earth ground beneath it is high. The cumulonimbus clouds tend to discharge the energy to maintain the potential. The energy is released in the form of flashes, which might lead to loss of lives.

Cloud to cloud-

This lightning occurs between separate clouds having different charge potentials. If it occurs between cloud, it is referred to as inter-cloud lightning; However, if the charge potential within a cloud is different, and a lightning flash is produced, Fulminologists refer to that as intra-cloud lightning (Rakov, &Uman, 2003)..

The intra-cloud and then inter-cloud occur between the cloud and then ground. The one occurring within the thunder cloud poses no hazard, but the flashes of lightning occurring between the cloud and the earth lead to destruction of buildings, infrastructures and lives.

Triggered lightning: This is the lightning caused by acts of man, for example, during the launch of lightning rockets etc

Extraterrestrial lightning-

These are the lightning’s that are registered in areas beyond the earth’s surface

Researches

While lightning has attracted a lot of attention among scholars and scientists, the most studied lightning is the cloud to ground lightning. This is so because of the magnitude and the prevalence in some areas. These areas exhibit similar characteristics such as large and tall skyscrapers, high population and extreme activities. The most prominent characteristics are the proximity and interaction to the skyscrapers, telecommunication systems, air planes, and other infrastructures. All these are naturally close to the thunderstorms and thus pose exceedingly significant threat. It is essential to realize that where as a single flash of lightning across the sky may only last for one second, it might contain an original return stroke and the two subsequent return strokes each lasting for approximately 90 milliseconds. Between the strokes there ere likely to be intervals of about 50 seconds

Rakov, &Uman, (2003), state that with each stroke, there appear mobile currents. These mobile electromagnet currents have a sub micro-second rise with insignificant fractional changes. It is also noteworthy that even if the electric flash encounters an electronic device, they are likely to spread to other adjacent areas causing interferences in the communication systems or electronically sensitive systems. The radiated electromagnetic waves with the negligible changes sometimes tend to interact antagonistically with avionics and other electronic devices (Munoz, 2003).

Recommendation for further research

Lightning are still a common phenomenon; however, there is a general belief that it has a connection with the metaphysical. It is imperative to understand the metaphysical aspects and the interconnectedness between scientific explanation of the causes of lightning and the religious beliefs. The fundamental understanding of lightning in the religious circles might offer an introduction to the metaphysics. Perhaps the religious explanation may be realistic based on the law of evolution. However, as meteorologists and scientists believe that the electrostatic changes between different Media are responsible for the lightning, we should focus on the possible intervention to these struck by lightning, in addition to why some areas are exceptionally prone to lightning. The electronic combustion of air by particularly powerful electric fields, which results into the production of forces on the charges and the subsequent flow of energy, needs further investigation for counter interaction. It is also beneficial to investigate the manner in which the potential energy carried by the electrostatic changes to thermal, light and the sound energies and how they are transmitted to the surface of the earth.

References

Munoz, R., (2003). “Factsheet: Lightning”. University Corporation for Atmospheric Research. Retrieved November 7, 2007.

Wang, D, Ushio, T; Kawasaki, T., (1995). “A possible way to trigger lightning using a laser”. Journal of Atmospheric and Terrestrial Physics 57 (5): 456–466.

Rakov, V; &Uman, M, (2003). Lightning: Physics and Effects, Cambridge University Press,