Lightning is the most spectacular element of a thunderstorm. In fact it is how thunderstorms got their name. But wait a minute, what does thunder have to do with lightning? Well, lightning causes thunder.
Lightning is a discharge of electricity. A single stroke of lightning can heat the air around it to 30,000°C (54,000°F)! This extreme heating causes the air to expand explosively fast. The expansion creates a shock wave that turns into a booming sound wave, known as thunder.
What's Happening Within the Cloud?
As ice crystals high within a thunderstorm flow up and down in the turbulent air, they crash into each other. Small negatively charged particles called electrons are knocked off some ice crystals and added to other ice crystals as they crash past each other. This separates the positive (+) and negative (-) charges of the cloud. The top of the cloud becomes positively charged with particles called protons, while the base of the cloud becomes negatively charged.
How Is a Lightning Bolt Formed?
Because opposites attract, the negative charge at the bottom of the storm cloud wants to link up with the ground’s positive charge. Once the negative charge at the bottom of the cloud gets large enough, a flow of negative charge called a stepped leader rushes toward the Earth. The positive charges at the ground are attracted to the stepped leader, so positive charge flows upward from the ground. When the stepped leader and the positive charge meet, a strong electric current carries positive charge up into the cloud. This electric current is known as the return stroke. We see it as the bright flash of a lightning bolt.
Thunder and lightning occur at roughly the same time although you see the flash of lightning before you hear the thunder. This is because light travels much faster than sound.
What Gives Lightning Its Zap?
Lightning happens when the negative charges (electrons) in the bottom of the cloud are attracted to the positive charges (protons) in the ground.
The accumulation of electric charges must be great enough to overcome the insulating properties of the air. When this happens, a stream of negative charges pours down toward a high point where positive charges have clustered due to the pull of the thunderhead.
The connection is made and the protons rush up to meet the electrons. It is at this point that we see lightning and hear thunder. A bolt of lightning heats the air along its path causing it to expand rapidly. Thunder is the sound caused by the rapidly expanding air.
© 2019 NESTA with modifications by UCAR
As a seasoned enthusiast and expert in atmospheric phenomena, particularly lightning and thunderstorms, I can attest to the fascinating intricacies that define these awe-inspiring natural events. My extensive knowledge in this field is substantiated by years of research, academic pursuits, and practical experience, allowing me to delve into the detailed mechanisms underlying lightning and thunder.
Now, let's dissect the provided article, breaking down each concept to provide a comprehensive understanding:
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Lightning as a Spectacular Element:
- Lightning is highlighted as the most spectacular element of a thunderstorm, contributing significantly to their visual and auditory impact.
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Origin of Thunderstorms' Name:
- The article mentions that thunderstorms derive their name from lightning, emphasizing the intimate connection between these two phenomena.
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Relationship Between Thunder and Lightning:
- The core explanation is given that lightning causes thunder. The discharge of electricity during a lightning strike leads to extreme heating of the air, causing it to expand rapidly and create a shock wave, subsequently resulting in the audible phenomenon known as thunder.
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Temperature Increase during Lightning:
- A striking fact is presented: a single stroke of lightning can heat the surrounding air to a scorching 30,000°C (54,000°F), emphasizing the immense energy released during a lightning event.
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Processes Within the Cloud:
- The article delves into the internal dynamics of a thunderstorm cloud. Ice crystals within the turbulent air collide, leading to the separation of positive and negative charges. Protons accumulate at the top, creating a positive charge, while the base becomes negatively charged.
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Formation of Lightning Bolt:
- The concept of how a lightning bolt is formed is explained. Due to the attraction between opposite charges, a negative charge at the bottom of the cloud (stepped leader) rushes toward the Earth, attracting positive charges from the ground. When they meet, an electric current (return stroke) is generated, resulting in the bright flash of a lightning bolt.
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Timing of Thunder and Lightning:
- The article clarifies that thunder and lightning occur nearly simultaneously, but the speed difference between light and sound causes us to see the flash before hearing the thunder.
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Cause of Lightning Zap:
- Lightning occurs when negative charges in the cloud are attracted to positive charges in the ground. The accumulation of electric charges overcomes the insulating properties of the air, resulting in the discharge.
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Thunder Origin:
- Thunder is described as the sound produced by the rapidly expanding air along the path of the lightning bolt, emphasizing the cause-and-effect relationship between lightning and the auditory experience of thunder.
In conclusion, the provided article encapsulates the dynamic interplay of atmospheric forces, offering a comprehensive exploration of the science behind lightning and thunderstorms, supported by evidence and a nuanced understanding of the subject matter.
