How do these electrical phenomena come about?

Today we know that, far from the celestial fury, we are facing a spectacle of nature in which its energy and power are evident. Even so, there are meteorological phenomena that still leave us in awe because even when we understand how they occur, that does not make them any less astonishing. Quite the contrary.

Electrical phenomena: What is lightning really?

When we talk about storms, it's very likely that we associate it with its most iconic element: A bolt of lightning. This is a discharge of electricity that occurs when enough opposite electrical charges (positive and negative) accumulate in clouds. Even though how this electrical discharge starts is still a subject for debate, ice that is part of a graupel, which is the name given to ice-covered snow particles inside clouds, is thought to create polarities and produces a difference in the electrical potential which generates an electrical discharge.

This phenomenon can reach 10,000 million kilowatts in an instant, and this is truly incredible if we compare it with the combined electrical power of the seven nuclear power plants in Spain which in 2022 reached 7,400 megawatts. As if this were not enough, lightning can also reach 30,000 degrees Celsius, a heat that is six times the temperature of the Sun's surface.

In fact, this causes a sudden rise in temperature that generates an explosion in the air that causes what we know as thunder, the characteristic sound that accompanies lightning which is the visible manifestation of a bolt of lightning.

Why do lightning bolts have that recognisable shape?

When we think of lightning, what comes to mind is that branching, zigzagging shape with a multitude of angles in different directions.

This is because, in the atmosphere, despite being invisible to the human eye, there are areas with greater or lesser resistance, since it is not homogeneous. That is why, when the electrical discharge is generated and the lightning travels at about 440 kilometres per second, it is in fact looking for the path that offers the least resistance which is why the typical shape is in the form of branches instead of a straight line.

Types of Electrical Phenomena That Exist

Now that we know how lightning originates and the reason for the rumble and that particular shape, it is time to learn about the different types that exist. The topic of electrical phenomena is very broad and may be due to changes that may occur in the wind, atmospheric pressure or humidity in the place where the storm is occurring. The following are the most common types of lightning:

Cloud-to-ground lightning

This is the most common type of electrical meteorological phenomenon, with a discharge that travels downwards, until it reaches the ground. As such, it can be dangerous and have destructive consequences for humans and animals.

A variant of this is bead lightning, when a number of lightning bolts appear around the main one.

Cloud-to-cloud lightning

When two clouds that are not joined together have an electrical potential difference, it can result in a discharge that travels horizontally, rather than vertically. In other words, the lightning originates in a cloud and reaches another that is nearby.

This can also occur within the same cloud, in which case it would be intracloud lightning.

And the rarest ones: Sprites

One of the most fascinating electrical phenomena that take place in the atmosphere is what is known as sprite lightning, a reddish phenomenon with a ghostly appearance.

Technically, sprites are part of what are known as Transient Luminous Events and are natural phenomena that occur in the mesosphere, the coldest layer of the Earth's atmosphere that is 50-90 kilometres above sea level.

These special spectres originate as a result of a powerful electrical field that occurs in the upper part of an electrical storm, when the cloud that has produced lightning towards the Earth's surface experiences a deficit of electrons. This generates a voltage that accelerates the electrons, which collide with the air molecules with great force and form this characteristic phenomenon.

The bad news is that their appearance and disappearance are so fleeting that they can only be recorded with special cameras. In addition to sprites, Transitory Luminous Events also include jets which are similar but bluish in colour, and then there is a kind of ellipse, which is called elves, a name given to them because they have a certain magic character. They have a diameter of approximately 400 km and rarely last as long as 0.001 sec.