Ultraviolet corona discharges on treetops during storms
1–10 of 69 posts
Re: Ultraviolet corona discharges on treetops during storms
#2Having lived in the PNW all my life, and worked closely with our friend Doug (the fir trees), this article brings up old mental images of otherwise healthy needles with browned (dead) tips in the crowns.
Coincidence? Probably.
Very cool phenomenon to catch visually.
Re: Ultraviolet corona discharges on treetops during storms
#3There is in fact no photograph of treetops glowing.
There is a digital UV-wavelength video of the corona, and a visible-wavelength video of the trees.
The paper [1] contains a sole picture with tiny circles indicating where the UV-video detected corona events, overlaid over a frame of the visible-wavelength video.
The paper does also contain a video [2] which overlays a somewhat processed version of the UV video over the visible wavelength video, where UV photon events are indicated by decaying red dots.
[1] https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2025GL11...
[2] https://agupubs.onlinelibrary.wiley.com/action/downloadSuppl...
Re: Ultraviolet corona discharges on treetops during storms
#4Having lived in the PNW all my life, and worked closely with our friend Doug (the fir trees), this article brings up old mental images of otherwise healthy needles with browned (dead) tips in the crowns. Coincidence? Probably. Very cool phenomenon to catch visually.
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Re: Ultraviolet corona discharges on treetops during storms
#5Great time to read about St Elmo's Fire!
Re: Ultraviolet corona discharges on treetops during storms
#6Storm troopers, but not the kind you'd expect.
Re: Ultraviolet corona discharges on treetops during storms
#7I notice the article, the paper, and the "plain language" summary of the paper don't mention the common term for this phenomenon, St Elmo's fire.
Re: Ultraviolet corona discharges on treetops during storms
#8There is in fact no photograph of treetops glowing. There is a digital UV-wavelength video of the corona, and a visible-wavelength video of the trees. The paper [1] contains a sole picture with tiny circles indicating where the UV-video detected corona events, overlaid over a frame of the visible-wavelength video. The paper does also contain a video [2] which overlays a somewhat processed version of the UV video over…
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Re: Ultraviolet corona discharges on treetops during storms
#9Great time to read about St Elmo's Fire! https://en.wikipedia.org/wiki/St._Elmo's_fire
Sounds like a man in motion :)
Re: Ultraviolet corona discharges on treetops during storms
#10There is in fact no photograph of treetops glowing. There is a digital UV-wavelength video of the corona, and a visible-wavelength video of the trees. The paper [1] contains a sole picture with tiny circles indicating where the UV-video detected corona events, overlaid over a frame of the visible-wavelength video. The paper does also contain a video [2] which overlays a somewhat processed version of the UV video over…
Sorry, in what way is this not a photograph? Are you saying that a video is not a sequence of photographs, that UV photons captured by a sensor don’t count because human retina sensitivity is low in that range, or some hopefully-less-semantic argument?