Lightning

Peter H. Meléndez Cardona

Sometimes we see a ray of light between the clouds and we ask ourselves what is that? And how is form? The name of this light is call a lightning and this lightning is a discharge of a large electrostatic charges that builds up on clouds near the surface of the earth during atmospheric disturbances such a thunderstorms. Scientist still doesn’t how the lightning forms they have studied different causes ranging from atmospheric perturbations: wind, humidity, friction, and atmospheric pressure to the impact of solar wind and accumulation of charged solar particles. Ice inside a cloud is thought to be a key element in lightning development, and may cause a forcible separation of positive and negative charges within the cloud and assisting in the formation of lightning.

Some lightning strikes have similar characteristics so scientists have given names to these various types of lightning. The streak lightning is the most common observed lightning. The majority of the lightning occurs inside the clouds so we do not see most of them. The types of lightning are Bead lightning, Ribbon lightning, Staccato lightning, Forked lightning, Ground to cloud Lightning, Cloud to cloud Lightning, Sheet lightning, Heat lightning, Dry Lightning, Rocket lightning, Ball lightning. But also there are positive and negative Lightning, the negative lightning has an average bolt that carries an electric current of 30 kiloampere (kA), and transfers a charge of five coulombs and 500 MJ of energy. Large bolts of lightning can carry up to 120 kA and 350 coulombs. Also the voltage is proportional to the length of the bolt. The positive lightning carries an electric current of 300 kA about 10 times the negative lightning. Lightning rapidly heats the air in its immediate proximity to around 20,000 °C (36,000 °F) almost three times the temperature of the surface of the Sun. This compresses the surrounding clear air and creates a supersonic shock wave, which decays to an acoustic wave that is heard as thunder. Thunder is the sound made by lightning. The louder you hear the thunder is the distance that the lightning is from the person. The lightning produces an increase in the pressure and temperature and this produce a rapid expansion of the air surrounding and within the bolt of lightning. In turn, this expansion of air creates a sonic shock wave, which produces the sound of thunder.

The movement of electrical charges produces a magnetic field. The intense currents of a lightning discharge create a fleeting but very strong magnetic field. The phenomenon of lightning-induced remnant magnetism is where the lightning current path passes through rock, soil, or metal these materials can become permanently magnetized. These currents follow the least resistive path, where faults, ore bodies, or ground water offers a less resistive path. Lightning-induced magnetic anomalies can be mapped in the ground, and analysis of magnetized materials can confirm lightning was the source of the magnetization and provide an estimate of the peak current of the lightning discharge.

Now we can understand what is a lightning and how is form, showing how natures work ways that we will never understand.