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Name: Sebastien
Status: other
Age: 20s
Location: N/A
Country: N/A
Date: 2000-2001


Question:
First excuse my English cause I speak french I heard that lightnings strike from the ground to the clouds Is that true?


Replies:
Dear Sebastien-

In response to your question about lightning, this is a copy of an answer to a similiar question I posted a few days ago...

You are correct in assuming that lightning can "strike" from the ground up. In fact, lightning does strike from different directions with each stroke..! The development of a bolt of lightning is very interesting. I won't go into all the details here, but a cloud-to-ground lightning bolt begins from the cloud in a series of "stepped leaders." As these leaders near the ground, a powerful "return stroke" of positive charge rushes up from the ground (at a speed up to 60,000 mph, or about 1/3 the speed of light) to meet the stepped leader. These static charges travel back and forth between the cloud and ground until the electrical potential is neutralized.

Three types of lightning are common... cloud-to-ground, cloud-to-cloud, and in-cloud. So lightning can travel up, down, and even sideways..!

Wendell Bechtold, Meteorologist
Forecaster, National Weather Service
Weather Forecast Office, St. Louis, MO


Sebastien,

Lightning develops as a result of a concentration of charge on the ground and an opposite charge in the cloud. A stepped leader starts from the ground and a leader meets it a few hundred meters above the ground. This ionizes a path for a lightning stroke, which goes up to the cloud from the ground (electrons stream from the cloud to the ground) and energy is transferred from the cloud to the ground.

David Cook
Argonne National Laboratory





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