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Travel A road trip in Burgundy reveals far more than fine wine. Travel My Hometown In L. Travel The last artists crafting a Thai royal treasure. Subscriber Exclusive Content. As the negative charge gets close to the ground, a positive charge, called a streamer, reaches up to meet the negative charge.
The channels connect and we see the lightning stroke. We may see several strokes using the same path, giving the lightning bolt a flickering appearance, before the electrical discharge is complete. That's five times hotter than the surface of the Sun! The heated air expands explosively, creating a shockwave as the surrounding air is rapidly compressed.
The air then contracts rapidly as it cools. If we are watching the sky, we see the lightning before we hear the thunder. That is because light travels much faster than sound waves. We can estimate the distance of the lightning by counting how many seconds it takes until we hear the thunder.
It takes approximately 5 seconds for the sound to travel 1 mile. If the thunder follows the lightning almost instantly, you know the lightning is too close for comfort! Lightning is an important part of weather forecasting. This complete picture of lightning at any given time will improve "now-casting" of dangerous thunderstorms, tornadoes, hail, and flash floods. What causes lightning? Wait a minute, what does thunder have to do with lightning?
Well, lightning causes thunder. Lightning is a discharge of electricity. 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. As ice crystals high within a thunderstorm cloud flow up and down in the turbulent air, they crash into each other.
Small negatively charged particles called electrons are knocked off some ice and added to other ice as they crash past each other. The top of the cloud becomes positively charged while the base of the cloud becomes negatively charged. 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.
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