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Published byPercival Sherman Armstrong Modified over 9 years ago
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Lightning The Shocking Truth of How it Works
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The Strike – it starts in the cloud The strike begins in the cloud itself. Clouds contain both hail stones and frozen water droplets (ice crystals) When the hailstones collide with the ice crystals, they gain electrons. The lighter (positively charged) ice crystals rise towards the top of the cloud while the negatively charged hailstones sink towards the bottom.
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The Strike…It’s all about attraction The negatively charged bottom edge of the cloud attracts positive charges on the surface of the Earth.
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The Strike…It’s all about attraction The electric charge on the bottom of the cloud builds until it overcomes the insulating properties of the air. Air separates into positive and negative ions – this is called Ionization. The ionized air (also called a plasma) allows for the movement of electrons.
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The Strike…Leading the Way Once the air has been ionized, several possible paths are created for electrons. Each of these paths are called Leaders or Step Leaders. *Air does not ionize equally in all directions – that’s why lightning looks so jagged. As the leaders make their way to the Earth, the positive charges in the ground reach up to meet the them (these are called Positive Streamers)
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The Strike…Kaboom So when the leader meets the positive charges from the ground… This is NOT the lightning strike. The leader provides the pathway for the electrons that transfer from the cloud to the ground. So when the transfer of electrons from the cloud to the ground occurs…KABOOM!
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In Motion…
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What we actually see and hear The Flash -This is created by the sudden discharge of electrons *The Heat - Lightning is basically a HUGE electrical current and electrical currents generate heat. Did You Know? The average temperature of a lightning bolt is between 40,000 to 50,000 o F. The surface of the Sun is only approximately 10,000 o F. The air around a bolt of lightning heats up and expands so rapidly – it explodes. Thunder is a result of the shock wave created by the exploding air.
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Here comes the Thunder Thunder is the sound of the exploding air. The exploding air also sends out a shockwave that can be felt by observers at a close distance. (This is when thunder rattles objects nearby). Because light travels faster than sound, we see the flash before we hear the thunder (that is unless you are VERY close)
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Steps to a Lightning Strike (Six Steps) Step 1 – Positive and negative charges separate (polarize) within the cloud. Step 2 – Negative charges accumulate along the bottom of the cloud. Positive charges accumulate on the ground. Step 3 – Charges grow Step 4 – Air between cloud and ground ionizes (separates into positive and negative ions.) Allows electrons to flow. Step 5 – Electrons from the cloud connect with positive charges from the ground and create a ‘pathway’ for electrical charge. Step 6 – Electrons are discharged from the cloud to the ground. The discharge results in the flash and crack of lightning.
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Kinds of Lightning Strikes Cloud to Ground – already discussed Ground to Cloud (Upward Lightning) – initiated by very tall, often metallic objects. Cloud to Cloud – Lightning that travels from one segment of a thundercloud to another.
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