Lightning strikes go upwards?

I saw a documentary that mentioned that the majority of the victims' burns was due to the diesel fuel (for the propulsion motors) that kept burning long after all the H2 had gone...

I have heard it before, that lightning strikes actually go from the ground up. I was just watching a YouTube video that shows it. Using HTML5 with the ability to slow down the video to frame by frame, you can see the first frame shows the bolt apparently coming from the lightning rod. It's the first time I've seen evidence of that claim.

if you don't have the skillz to slow the video down, you can see my reply to my own post.

Something else notable is all the activity clearly comes after the charge leaves the lightning rod.

Most lightning propagates downward from negatively-charged (~95%) or positively-charged storm cloud regions (~5%) in a series of weakly ionized plasma as stepped leaders (negative) or smoothly propagating positive leaders. These split into multiple channels and they head downward seeking ground. The leaders carry relatively low current (only tens to hundreds of amps). As the leaders get closer to ground, they elevate the surface E-field at the top of nearby objects (tree tops, buildings, light poles, people). Corona and then oppositely-charged plasma streamers are initiated from high points, growing up towards the descending leaders. When a downward and upward pair connect, a huge current (tens to hundreds of kA) flows upward from the earth back to the clouds. This is the return stroke - the main lightning stroke that we see and hear. So even though lightning leaders propagate downward for most of their journey, the main high-current lightning bolt actually races back upward through one of the leader channels, heating the channel.

Lightning CAN be initiated from high objects to form branching discharges that grow upward into the clouds above. This can sometimes be seen to originate from the tops of transmitter towers, skyscrapers, and mountains. Some examples:

Bert

Amazing. This might be a decent read...

No. You see the human eye visible photonic emission illumination of the plasma "going up". That does not mean the plasma itself was travelling in that direction.

That by no means indicates "upward flow"

The Earth is the BIGGEST attractor. ANY accumulation of excess electrons is going to dump INTO the Earth, NOT into the sky.

The DISCHARGE *from* the sky ENTERS the lightning rod.

My recollection is that in most lightning strokes,

- A negatively-charged "leader" comes down from the cloud. Path is often jagged and very irregular. There's some reason to believe that the "leader" sometimes, or even mostly- always follows the path of a "particle shower" triggered by a cosmic ray striking the atmosphere.

The leader is a relatively low-current affair and is often not very bright.

- Once the negative "leader" comes close enough to ground, the electrical field strength can trigger corona discharge and upwards "streamers" from objects on the ground, such as trees and lightning rods.

- When the negative leader and positive streamers connect, BOOM. You have an ionized (and conductive) channel from ground to cloud, and a strong positive current flows upwards. This is usually the brightest part of the lightning stroke.

So, the YouTube video mentioned above, may be showing a strike in which there was an initial negative "leader" which wasn't bright enough to be visible, or which ended up out of the camera's field of view. The positive "streamer" would have arisen from the lightning rod, in response to the strong electrical field created by the approaching negative "leader".

In any case, a typical lightning "stroke" is a complex phenomenon. It doesn't have a single "direction" - ionized, conductive channels "grow from both ends", and the bright portion of the stroke occurs after they meet in the middle.

Well, it might be 1 nF. It goes as the radius, so if you're really 200 pF, you seem to be about 12 feet in diameter. Might want to lay off the french fries for a bit. ;)

Cheers

Phil Hobbs

Well not too many french fries... But less beer would help the waist line.

Here's a 'scope shot

Discharge through 10 Meg ohm 'scope probe. (You have to screw around a bit to get the right amount of charge) I always get something a bit more than 2 ms.

George H.