Both at the same time!, lightning has been photgraphed heading upwards from trees, at the same time leaders head downwards as well, where they meet a lightning strike occours.
Thats why when you are out in the open during a storm and feel your hair standing on end - panic and get down, a leader may be leaving your head!
2006-11-29 00:37:41
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answer #1
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answered by thecoldvoiceofreason 6
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When sufficient negative and positive charges gather, and when the electric field becomes sufficiently strong, an electrical discharge (the bolt of lightning) occurs within clouds or between clouds and the ground. During the strike, successive portions of air become conductive as the electrons and positive ions of air molecules are pulled away from each other and forced to flow in opposite directions.
As the cloud progresses over the Earth's surface, an equal but opposite charge is induced in the Earth below, and the induced ground charge follows the movement of the cloud. When a step leader approaches the ground, the presence of opposite charges on the ground enhances the electric field. The electric field is highest on trees and tall buildings. If the electric field is strong enough, a conductive discharge (called a positive streamer) can develop from these points. This was first theorized by Heinz Kasemir. As the field increases, the positive streamer may evolve into a hotter, higher current leader which eventually connects to the descending stepped leader from the cloud. It is also possible for many streamers to develop from many different objects simultaneously, with only one connecting with the leader and forming the main discharge path. Photographs have been taken on which non-connected streamers are clearly visible. When the two leaders meet, the electric current greatly increases. The region of high current propagates back up the positive stepped leader into the cloud with a "return stroke" that is the most luminous part of the lightning discharge. Lightning can also occur within the ash clouds from volcanic eruptions,or can be caused by violent forest fires which generate sufficient dust to create a static charge.
2006-11-29 00:50:13
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answer #2
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answered by Anonymous
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Lightning is a transmission of energy from a high potential to a low potential. The terminals can be either cloud or earth ... meaning the charge will travel from cloud to cloud, or cloud to earth.
The cloud bottom carries a negative charge. Positive charges may collect on other clouds, the ground, buildings, boat masts, people, flagpoles, mountaintops, or trees.
A stepped leader—a negative electrical charge made of zig-zagging segments, or steps—comes partway down the path between the objects. The steps are invisible; each one is about 150 feet long.
When the stepped leader gets within 150 feet of a positive charge, a streamer (surge of positive electricity) moves to meet it. The leader and the streamer make a channel.
An electrical current from the object with higher potential (remember, this could be another cloud!) surges upward through the channel. It touches off a bright display called a return stroke.
2006-11-29 00:41:17
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answer #3
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answered by CanTexan 6
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Both, the some of strikes also occur above the clouds. It depends on th + & - charges at ground locations composed with what is generated over head. Lightning also occurs above the clouds and can travel up.
2006-11-29 00:37:20
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answer #4
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answered by Anonymous
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Yep, the two. A stepped chief would descend from the clouds or ascend from the floor or the two and meet close to the midway factor. as quickly as a pathway is set up a pulse will return and forth up or down this pathway and there may well be many pulses. It take place so speedy that in the time of basic terms an extremely extreme velocity digital camera can seize it.
2016-10-13 08:31:53
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answer #5
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answered by ? 4
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From the earth up to the clouds because the earth is negatively charged.
2006-11-29 00:30:26
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answer #6
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answered by Anonymous
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up to the cloud but also from above the clouds into space where mega lightning is concerned.
2006-11-29 00:59:54
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answer #7
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answered by Definately Maybe 5
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Lightning actually comes from the ground.
2006-11-29 00:30:44
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answer #8
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answered by Carrie 2
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Either ways. The clouds are ionized--they can be positively ionized or negatively ionized. Since earth is electrical Ground, the charge can flow either way.
2006-11-29 00:39:18
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answer #9
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answered by ravish2006 6
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A `leader` goes down and the main charge goes up it.
2006-11-29 00:30:27
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answer #10
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answered by Spanner 6
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