Electric discharges {lightning}| can go between clouds or between clouds and ground. Strength can be 10^8 volts. Lightning strikes 44,000 times a day and makes 200 forest fires a day. Lightning can be streaks or sheets. Rare lightning form is hot ionized gas {ball lightning}. Lightning makes nitrous oxide, which fertilizes soil.
process
As warm air rushes up and raindrops fall, they rub each other and separate charges, making voltage. If charge path is between cloud and ground or another cloud, first a thin current streak {leader, lightning} flows, followed by main discharge at more than 1000 amperes for 10^-2 seconds.
Metal conductors {lightning rod}| can conduct lightning current into ground, to dissipate it.
Lightning heats air suddenly and expands it rapidly, making noise {thunder}| as shock waves. People can hear thunder up to 15 kilometers away.
Lightning can make radio waves {whistler}| that strike magnetosphere and come back along magnetic-force lines. High frequencies come back first, followed by low frequencies.
Lightning {blue jet} can flash between upper clouds and ionosphere, 44 to 50 miles away, in tree-like structure.
Far-away lightning reflections {heat lightning} can be on horizon clouds on hot summer evenings. Thunder is too far away to hear.
Lightning can cause mushroom-shaped flashes {red sprite} in ionosphere.
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Date Modified: 2022.0225