Until recently, I thought that lightning went either from cloud-to-cloud or cloud-to-ground…but I read somewhere (can’t remember) that the visual bolt actually eminates from the ground and goes up to the cloud. If this is true, what is the point of not standing under a tree? Does it become a transmission tower for all the charge in the ground??
Very confused.
From www.exploratorium.edu/ronh/weather/weather.html
Thunder is good, thunder is impressive; but it is lightning that does the work. - Mark Twain
Sig! Sig a Sog! Sig it loud! Sig it Strog! – Karen Carpenter with a head cold
Lighting can work both ways. Cloud to cloud, cloud to ground, ground to cloud, or from ground and from cloud meeting each other.
Oops, almost forgot:
Because the tree (or any other high point) is the closest point of contact to the earth. The leader stroke from the cloud will always take the path of least resistance, and that usually means the shortest route as well.
Sig! Sig a Sog! Sig it loud! Sig it Strog! – Karen Carpenter with a head cold
Someone much sharper than I will probably answer this but I’ll give it a go.
Lightening travels in two directions.
Th cloud base wiil charge up to a huge potential which will draw tracers from ground based objects.
These tracers tend to form around pointy things-a rounded point is the best hence the shape of lightening conductors-and form a charged path toward the cloud potential.
At some point the tracer gets near enough to the cloud for the cloud potential to draw itself across the air gap which then fires its charge earthwards.
Usually there are several return strikes as not all the cloud will release its charge in one go,these extra strikes take the already established path down to earth.
You can see this happening in photographs some intrepid individuals have managed to obtain, the main strike is visible and so too are tracers which have been drawn up but never made it to the cloud base.
Tracers can form on anything ,for instance, if you are the highest object around during a storm you may feel your hair being drawn vertically upward,you are now in very grave danger as a tracer has formed from your head.
In the absence of very nearby shelter you must lie down in the hope another tracer from elswhere makes it to the cloud first.It it does not then at least the strike is going to travel through less of your body and the strike area will be more spread out giving you,hopefully ,a better chance of survival.
DO NOT stand near a tree.If it is struck the fluids in it will heat up incredibly rapidly,these expand explosively .If the blast does not kill you then the falling material probably will.
And that’s why a number lightning-strike survivors have reported feeling their hair stand on end just before the strike.
I saw a picture taken with extremely fast shutter showing streamers rising from objects just before a strike. You could see these thin, crooked lines of light rising from a telephone pole, tree, etc., but only one actually hooked up the the lightning bolt. (This was from Acts of God, a fascinating book of weather anecdotes published by the Farmer’s Almanac)
Imbibo, ergo sum.
Curses! Simulpost!
In this picture you can see a pair of streamers rising from ground-based sources - one from the tree and one from the house’s television antenna.
Bet this was the picture y’all were talking about, eh?
Just rehashing what everyone else has already said:
Here’s the Weather Channel’s webpage with information on what occurs during lightning strikes.
http://www.weather.com/breaking_weather/encyclopedia/thunder/light.html
God is my co-pilot. Blame Him.