Eyjafjallajokull volcano lightning

[Heretic]

Eyjafjallajokull volcano emits lightning bolts. I think that is awesome stuff right there.

[Duper]

is it me, or does that middle picture look like that dog/dragon from Never ending story?

[Sergeant Thorne]

Wow. Great photos. That is awesome!

[TechPro]

is it me, or does that middle picture look like that dog/dragon from Never ending story?

Yeah, Falcore. The Luck Dragon. (long bodied huge flying ... dog) Hey, I got kids.

[Heretic]

Wow didn't notice him must be running from the Nothing

[Duper]

is it me, or does that middle picture look like that dog/dragon from Never ending story?

Yeah, Falcore. The Luck Dragon. (long bodied huge flying ... dog) Hey, I got kids.

AAahhh. Thanks. It was right the tip of my tongue. Those are some really awesome picts.

Nice post Heri.

[Sirius]

Bing had a nice one too: http://www.bing.com/fd/hpk2/IcelandErup ... 775224.jpg

Doesn't even look real... but there you are.

[EngDrewman]

Does anyone know what causes this volcano to emit lightning? Is the ash plume somehow conductive and reach high enough in the atmosphere like a cumulonimbus cloud?

[Top Gun]

Basically, you have a bunch of tiny ash particles rubbing against each other at high speeds and building up a massive charge of static electricity, just as ice particles do in a normal thunderstorm. Eventually, the charge becomes strong enough that it discharges between oppositely-charged regions of the ash cloud.

[Duper]

Basically, you have a bunch of tiny ash particles rubbing against each other at high speeds and building up a massive charge of static electricity, just as ice particles do in a normal thunderstorm. Eventually, the charge becomes strong enough that it discharges between oppositely-charged regions of the ash cloud.

yup yup!

we had the same thing with Mt. Saint Helen's in 1980. (its about 30 miles away.)

[Spidey]

Yea, charged particles is definitely the answer…but…there is still some debate going on, as to just how they get charged.

Don't yell at me...that's what I read.

[Duper]

ya know, I read that too. I can't figure. It seems rather obvious, but then I'm told that lightning actually arcs from the ground up, not the other way around....

[Spidey]

Yes the new science of lightning is very confusing, the conventional theory is…

Electrons always flow from negative to positive, so the flow of electrons in a lightning strike is from the negatively charged clouds to the ground.

The new science is that it's the “holes” (positive charges) that make the flash…not the flow of electrons.

And, I have also heard that the earth is positively charged, but the surface is negatively charged…

So go figure.

[Krom]

The earth is positively charged, the atmosphere is negatively charged (typically). The direction of the current flow of most lightning strikes is from the sky to the ground. However the way a lightning bolt visibly propagates when it fans out often appears to start from the ground and then spread higher and wider. This is because its the plasma created by the previous flash gives other charged regions of the cloud a lower resistance path to ground and the process of connecting all these regions and segments isn't instant.

The bolt first flashes where the initial connection to the ground is, that segment of the bolt is then discharged, but the plasma remains for a moment and provides a long conductor from the ground into the cloud for further charged regions to arc to. Now a branch of the bolt or the fan can be close enough that it too will make a connection to the plasma and then discharge, the whole length of plasma from that point back to the ground will then flare up again with the addition of the new branch, that will also provide the same effect to even more branches further along its own path. So the visible effect makes it appear like the bolt starts at the ground and spreads up and out, but the current can still be flowing from the cloud into the ground.

[woodchip]

The really odd lightening is from the clouds up into space

[Duper]

I've never actually seen that before Krom. I've always seen lightning go from the sky to the ground. .. if it even reaches.

(oh well)

My Mom has actually seen ball lightning.

[Spidey]

I think what Duper called “arcing from the ground up” is what they are now referring to as the “return stroke” which is the “visible” part, after the negative charge “steps” down from the clouds.

[AlphaDoG]