• After witnessing the continued decrease of involvement in the SpotterNetwork staff in serving SN members with troubleshooting issues recently, I have unilaterally decided to terminate the relationship between SpotterNetwork's support and Stormtrack. I have witnessed multiple users unable to receive support weeks after initiating help threads on the forum. I find this lack of response from SpotterNetwork officials disappointing and a failure to hold up their end of the agreement that was made years ago, before I took over management of this site. In my opinion, having Stormtrack users sit and wait for so long to receive help on SpotterNetwork issues on the Stormtrack forums reflects poorly not only on SpotterNetwork, but on Stormtrack and (by association) me as well. Since the issue has not been satisfactorily addressed, I no longer wish for the Stormtrack forum to be associated with SpotterNetwork.

    I apologize to those who continue to have issues with the service and continue to see their issues left unaddressed. Please understand that the connection between ST and SN was put in place long before I had any say over it. But now that I am the "captain of this ship," it is within my right (nay, duty) to make adjustments as I see necessary. Ending this relationship is such an adjustment.

    For those who continue to need help, I recommend navigating a web browswer to SpotterNetwork's About page, and seeking the individuals listed on that page for all further inquiries about SpotterNetwork.

    From this moment forward, the SpotterNetwork sub-forum has been hidden/deleted and there will be no assurance that any SpotterNetwork issues brought up in any of Stormtrack's other sub-forums will be addressed. Do not rely on Stormtrack for help with SpotterNetwork issues.

    Sincerely, Jeff D.

Small-scale features on tower lightning video

  • Thread starter Thread starter Dan Robinson
  • Start date Start date

Dan Robinson

I did some analyzing of the tower lightning video tonight and found a few of interesting features.

Here is a slow-motion, full-screen WMV video clip (1.8MB):
http://wvlightning.com/chase2005/video/leaders.wmv

Upward-propagating leaders are visible prior to all of the strikes on the wide-angle versions of the video.

leader.jpg


leader1.jpg


leader2.jpg


These features can be differentiated from false 'ghost channel' artifacts common on lightning video. Video is prone to 'ghosting' of the lightning channel on the frame preceding the stroke, but the 'ghost channel' is always shifted downward on the video frame, making the channel appear to be a 'leader' propagating upward very close to the observer, such as in this example from another video:

ghost1a.jpg
ghost1b.jpg


The 'ghost artifact' is very apparent in this next example frame from another video, where a false 'ghost leader' appears to be striking me in the back!

headstrike2.jpg


In the above tower lightning clips, the leaders are in the exact same position and shape as the full stroke on the next video frame, eliminating the possibility of these features being video ghosting artifacts.

Another item of note is two small-scale features on the last return stroke of the second flash. One is a small horizontal leader jutting out from the antenna tip, the second is a downward-reaching branch connected to the main channel.

leader3.jpg


Contrast-enhancing allows these features to be seen more clearly:

leader3a.jpg


Again, it is not apparent that this is a video ghosting artifact.

It would be interesting to shoot this type of event with a high-speed camera to examine more of these small-scale features that we normally don't get to see.
 
Facinating! I agree, with the high speed video idea too. Would be neat to see more on this.
 
Wow, that's some video. I think it's interesting the way the tip of the tower flashes in the absence of a lightning bolt, at about 4.5 seconds — residual charge in the air, perhaps? A kind of St. Elmo's Fire?
 
Originally posted by Thomas Loades
Wow, that's some video. I think it's interesting the way the tip of the tower flashes in the absence of a lightning bolt, at about 4.5 seconds — residual charge in the air, perhaps? A kind of St. Elmo's Fire?

Or a flashing light on top of the tower? :)
 
Thanks for the comments!

The flashing near the top is one of the white strobe lights on the tower.
 
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