Does lightning come from the ground or the sky?

Question

Inn school I remember learning it goes from the ground up even though it does not appear that way.I told my daghter the other day and my husbans says I am crazy so I am just wondering .

Answer 1

Lightining from the ground would require a build up of negative charge in the Earth and positive charge in the atmoshphere. I would assume negative charge can build up on the Earth and positive charge definitely builds up in the atmosphere so yes i would say it is possible.

Answer 2

the electrical ions in the air collect and get excited and discharge

Answer 3

\Well, it doesn't from the ground, it comes from the sky to the ground ,possibly.

  

Answer 4

Yes, it goes both ways. My understanding is that a positive leader first moves up from the ground to a tall pointed object. That then attracts negative charge from the cloud, and current starts flowing, causing the bolt.

When you watch a bolt, it moves so fast, you really can't tell which direction it goes in.

for more info:

http://en.wikipedia.org/wiki/Lightning

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Answer 5

You're right. A cloud issues a negatively charged, very faint, "stepped leader" to the ground. As the leader gets close, a streamer of positive charge is drawn up from the higher objects on the ground. When the charges meet, an electrical pathway is opened and an intense return stroke travels upward. The return strokes are what we call lightning.

http://www.statesman.com/weather/content...

http://www.wrh.noaa.gov/fgz/science/ligh...

Answer 6

A little of both. It depends on what aspect of lighting you're concerned with (current or light). Ions move up and electrons move down. The current is carried mostly by electrons because they are smaller and more mobil, but the light is produced by ions which move up.

Being more mobil, it is the path prestrike electrons downward through the air which defines the path the current will eventually take. Since this early (trail blazing) path tends to branch out into different directions, the branching of a typical lighting strike is pointed downward.

Answer 7

As in anything, it takes two to tango. Lightning is no exception. Strikes happen in two basic ways. Cloud to cloud and cloud to ground. Indeed, the charge accumulates in the atmosphere and strikes another cloud or strikes the ground. Either way, the other object must be of different charge from where it originated, either in polarity or quantity. I could go on and on for many pages. Here's a bolt in a nutshell. Charge accumulates in a cloud. It builds up until the charge difference exceeds the breakdown point of the air. A leader bolt surges down to the nearest (highest) point on the ground. Just before it touches the ground, many "fingers" around the ground reach up to meet the leader coming down. These fingers can come from anything in the area. A garbage can lid, a fence post, the hood of your car, the top of your head. The finger that is closest to the leader will greet and meet the leader. The bolt is complete. The other fingers are failures and nothing happens with them. Hopefully it wasn't anyone's head.