What is lightning and how it is created

What are the consequences of a lightning strike, can you determine the distance to lightning by sound, and how to protect yourself during a thunderstorm.

Simple answers to common questions.

What is lightning?

Lightning is a cloud-generated type of intense spark discharge that occurs in a mass of charged and well-insulated particles (the average distance between them is two orders of magnitude larger than their size). This explanation of the natural phenomenon is given in the Great Ukrainian Encyclopedia.

The temperature inside lightning reaches 30,000 °C. In length, it can extend several tens of kilometers. The record is 321 km. The longest-lasting lightning strike recorded was 7.74 seconds.

How is lightning different from a thunderstorm?

A thunderstorm is an atmospheric phenomenon during which electrical discharges—lightning—occur inside clouds, between them, or between a cloud and the Earth’s surface, accompanied by thunder, heavy rain, and often gusty winds. Thus, lightning is part of a thunderstorm, just like thunder.

Lightning is a powerful electrical spark discharge in the atmosphere that raises air temperature to approximately 30,000 °C, while thunder is the sonic accompaniment of a thunderstorm—a loud shockwave resulting from a lightning discharge due to the collision of high- and low-pressure zones.

The so-called “dry lightning” is especially dangerous, as it is not accompanied by rain.

How lightning forms: in simple terms

About 1.4 billion lightning discharges occur in Earth’s atmosphere annually. Fortunately, most of them do not reach the planet’s surface, releasing electrical energy between clouds. Only the remaining 25% pose a danger.

Lightning most often forms in a cloud simultaneously in two opposite directions—descending toward the ground and ascending into the ionosphere, which can only be distinguished from space.

In most cases, lightning forms inside thunderclouds, as well as within large stratiform rain clouds and cumulonimbus clouds.

How does this happen? Clouds consist of water vapor, the droplets of which freeze at high altitudes, turning into ice crystals. Heated air is distributed unevenly, causing small ice crystals to rise while larger ones descend. During their collision and friction, an electric charge is generated. Small crystals carry a positive charge, while larger ones carry a negative charge. This difference requires discharge, resulting in lightning.

What types of lightning exist?

1. Forked lightning — one of the most common types of lightning. It is a long electrical discharge with small side branches. The flash lasts no more than 0.5 seconds. It has three subtypes:
   – cloud-to-ground;
   – ground-to-cloud; forms due to the “breakdown” of the air gap between the top of a charged object on the ground and the lower part of a thundercloud;
   – cloud-to-cloud; among the longest—up to 150 km, most often observed in tropical latitudes; looks spectacular, as if clouds are shooting fire arrows at each other.
2. Zigzag lightning — has a zigzag trajectory and sometimes pulsating glow.
3. Horizontal lightning — spreads horizontally across the sky, sometimes without thunderclouds. It is highly powerful and poses a serious threat to airplanes and helicopters.
4. Ribbon lightning — appears as several zigzag discharges from clouds to the ground, parallelly displaced relative to each other with small gaps or none at all.
5. Beaded (dotted lightning) — a rare form of electrical discharge during a thunderstorm, appearing as a chain of bright dots. It does not branch and has a wavy pattern.
6. Ball lightning — a wide vertical band of light, almost always accompanied by a low, quiet hum.
7. Sprite — a type of lightning that shoots upward from a cloud. A rare and poorly understood phenomenon.
8. Elf — lightning in the form of a huge cone-shaped flash about 400 km in diameter, weakly glowing, forming in the upper part of a thundercloud.
9. Sheet lightning — a white or reddish flash under low semi-transparent cloudiness, with a loud cracking sound, as if coming from all sides at once. Usually appears before an approaching thunderstorm.
10. Jet — lightning in the form of a tube-cone, mostly blue, up to 70 km high.
11. St. Elmo’s Fire — an electrical discharge in the form of glowing beams or brushes that occurs on the sharp ends of tall objects under increased atmospheric electric field intensity. Observed not only during thunderstorms but also in winter blizzards.
12. Heat lightning — a rare type of lightning, often not accompanied by thunder or rain, occurring in warm seasons.
13. Volcanic lightning — a discharge generated by magma and ash bubbles during a volcanic eruption.

How many volts are in a lightning bolt?

According to meteorologists, the current strength of lightning is measured in hundreds of thousands of amperes, its speed can reach 100 km/s, the spark discharge can lead to atmospheric electric field intensity of about 25-50 kV/m, and the potential difference along its path can reach hundreds of millions, up to a billion volts.

However, modern metal structures are not threatened by such strikes, as they are protected by special systems.

The Statue of Liberty is one of the largest lightning rods. Lightning strikes the Statue of Liberty several times a year. But the monument is grounded with four cables, so the elements do not harm it.

The Burj Khalifa—an 830-meter skyscraper that has survived countless thunderstorms—has one of the most advanced lightning protection systems in the world. The upper part of the tower is covered with panels containing special sensors that monitor atmospheric conditions. As soon as conditions for lightning formation arise, the sensors determine the polarity (+/-), and the panels create an opposite charge on the lightning rod mast, attracting all lightning discharges.

Lightning strike

The trajectory of lightning is unpredictable; in most cases, the bolt moves in a zigzag pattern. It is especially difficult to predict lightning movement on flat or uniform surfaces, such as a parking lot. However, lightning usually targets the highest point.

The most common discharge is “cloud-to-ground.” Its duration ranges from 60 to 100 microseconds, with an average speed of about 150 km/s. The shockwave force can reach 100 kilograms per square centimeter. The discharge power in some cases can reach 200 kA (kiloamperes) and 1000 kV.

Lightning strikes near or in warehouses and factories containing flammable or explosive materials are particularly dangerous. In such cases, the threat comes not only from the lightning itself but also from induced electrostatic voltage, which can cause a spark that may trigger an explosion or a massive fire. This applies not only to direct strikes on buildings or tanks but also to highly charged pre-thunderstorm atmospheres. Therefore, lightning protection at such facilities is maximized, including static electricity dissipation systems.

What attracts lightning?

• Lightning is attracted to spires in big cities.
• Isolated trees; it has been proven that lightning often strikes trees that have already been struck before.
• Streetlights and any spires.
• Chimneys and drainpipes.
• Satellite or internet antennas.
• External TV signal amplifiers.
• Weather vanes.
• Haystacks in the middle of a field or backyard.
• Bodies of water and swimming pools.
• Up to 6,000 people die from lightning strikes worldwide each year. The most affected are residents of Venezuela, Africa, Brazil, Singapore, and the USA.

What happens if lightning strikes a car?

People inside a stationary car will not be harmed by a direct lightning strike, as the entire discharge will be absorbed by the car’s body. The most important thing at this moment is not to touch the metal parts of the car. Most often, lightning strikes the radio or navigation system antenna, burning a hole in the roof or windshield.

If lightning strikes a moving car, it can disable electronic systems and blind the driver, posing an accident risk. If the discharge hits the fuel tank, the engine instantly seizes. A ground strike can melt asphalt, tires, and car rims.

A direct lightning strike is dangerous due to the subsequent risk of the car catching fire.

What happens if lightning strikes a house?

A house without a grounded lightning rod is highly likely to catch fire. And not just from the discharge itself but also from the released thermal energy. The amount of heat depends on the resistance of the building material. The higher the resistance, the more heat is generated. The most vulnerable are wooden and panel houses with ungrounded reinforcement. Brick houses are safer, as they poorly conduct heat and electrical discharges.

Areas with high groundwater levels increase the risk of lightning strikes. Nearby flammable materials, haystacks, grain storage, antennas, and weather vanes also increase the likelihood of lightning strikes and subsequent fires.

What happens if lightning strikes a person?

If a person is struck by lightning, the chances of survival are low. Most victims die instantly from cardiac arrest caused by the electric shock. Many suffer ruptured eardrums and eye blood vessels due to the sudden pressure change. Additionally, the discharge instantly disrupts heart rhythm, paralyzes the respiratory system, and leaves severe burns on the body as a result of ignited hair and clothing.

However, a lightning strike is not always fatal. The discharge can pass through the body in fractions of a second, leaving no external marks. But even in such cases, the victim may suffer nerve damage, post-traumatic stress disorder, and symptoms similar to a concussion. The consequences of a lightning strike are unpredictable. Some experience partial memory loss or complete amnesia. Others are left with distinctive marks called “Lichtenberg figures,” resulting from dehydration and damaged blood vessels. Some endure lifelong pain. Everything is highly individual.

The sad world record holder for the most lightning strikes is Roy Sullivan, who was struck seven times.

Why does lightning strike a person?

The most common factors are:

• The person becomes part of the electrical discharge channel and is hit directly.
• Lightning strikes a tall object and redirects some of its energy to a lower object, which could be a person, especially one using a cell phone. This is called a side flash.
• A person in active motion can attract a lightning strike.
• Ground voltage from a nearby lightning strike can also electrocute a person.

How to protect yourself from a lightning strike: 15 basic safety rules

1. When in a forest or urban park area, move away from tall trees. The taller the tree, the higher the risk of lightning striking it. Do not touch the trunk.
   Do not seek shelter under a solitary tree.
2. If you cannot leave the forest, crouch in a depression or under a low, bushy tree without a prominent top.
3. Turn off your cell phone.
4. Never lie on the ground during a thunderstorm.
5. If caught in a thunderstorm in the city, leave open spaces and take shelter indoors: a store, pharmacy, café, or building entrance. Remember: all city buildings are protected by lightning rods.
6. Do not seek shelter inside public transport stops or near metal structures and power stations.
7. While indoors, avoid using electrical appliances and do not touch faucets, pipes, or radiators.
8. In a private house, remember that chimney smoke has high electrical conductivity, increasing the chances of lightning striking the chimney.
9. Close windows and avoid balconies, even if you want to breathe in the ozone-rich thunderstorm air.
10. If caught in a car during a thunderstorm, stop driving, pull over, turn off the engine, and lower the antenna.
11. Motorcycles and bicycles are potentially dangerous during a thunderstorm. Stop, lay the vehicle on the ground, and move at least 30 meters away.
12. Do not swim, fish, or boat during a thunderstorm. Avoid being near bodies of water.
13. Do not run from a potential lightning strike; move calmly.
14. Avoid campfires during a thunderstorm. Remember point 9 about the conductivity of hot smoke.
15. Emergency phone number: 112.

Which trees are least likely to be struck by lightning?

It is believed that poplars, oaks, pines, and spruces are most frequently struck by lightning.

Maple, birch, and hazel trees are rarely struck.

How to determine the distance to lightning by sound

Example of calculating lightning distance by sound

Distance = number of seconds * 340 m/s

(340 m/s — speed of sound in air)

Example: L = 2 s * 340 m/s = 600 m

The speed of sound is 331.3 m/s in dry air at 0 °C and about 346 m/s at 28 °C. These values are averaged to 340 m/s. Thus, sound travels approximately 1 kilometer in 3 seconds. The speed of light is much higher—about 299,800 km/s.

To determine the distance to lightning by sound, simple arithmetic is needed. Upon seeing lightning, start counting seconds until thunder is heard, then divide the number of seconds by 3. The answer will give the distance in kilometers.

For example: if you count 30 seconds, the lightning is about 10 kilometers away; 12 seconds means 4 kilometers.

There is also the 30-30 rule, where the first value is the time in seconds signaling thunderstorm proximity (i.e., it is already within 10 km), and the second is the time in minutes to stay sheltered after the last lightning strike to avoid residual electric charge.

Places where lightning strikes most frequently

In 2016, American and Brazilian meteorologists published a ranking of the world’s most dangerous places with the highest frequency of lightning strikes. They analyzed data from the Tropical Rainfall Measuring Mission satellite from 1997 to 2015. Dividing Earth into grids and studying thunderstorm activity, they identified 500 spots most prone to lightning strikes. The team’s article, led by Dr. Rachel Albrecht, was published in the “Bulletin of the American Meteorological Society.”

It turned out that lightning strikes most frequently in South and Central Africa, as well as South America. The main lightning hotspot is the village of Kifuka in the Congo, which experiences 158 lightning strikes per square meter annually!

Another “magnet” for lightning is Lake Maracaibo in Venezuela. It is famous worldwide for the unique phenomenon called Catatumbo lightning. At the point where the Catatumbo River flows into Lake Maracaibo, the highest probability of lightning strikes is recorded—250 lightning strikes per square kilometer per year. At peak activity—from May to October, during nighttime from about 7 PM to 4 AM—up to 28 lightning strikes per minute have been recorded. Venezuelans call them “eternal lightning,” and local aviators use them as a navigational aid, calling them the “Beacon of Maracaibo.”

Why do thunderstorms occur so frequently here? Scientists believe it is due to a combination of natural conditions—winds blowing from the Andes and methane released into the atmosphere by swampy areas. Evidence that lightning in Maracaibo has always been present is found in Lope de Vega’s poem “The Dragontea,” which describes this unique phenomenon.