There 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.
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?
Having 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.
> Visually, the corona discharges generated on the leaves were either small purple-blue point discharges or elongated purple-blue discharges, and usually formed on the tips of the leaf closest to the source of the electric field (Figure 1). Sometimes the corona discharges were steady and constant, but other times they would dim and brighten in an unsteady pulse. When the corona was turned off, the tips of the leaf where the discharges occurred were often burned and browned, even for the weakest electric fields applied to the leaves.
Human eyes can be sensitive down to 380nm, the UV range goes up to 400nm. Birds and insects can see this. We can see this, using UV filters such as shown in the article. I get that it's fun to be a pedant sometimes, but come on.
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...
Coincidence? Probably.
Very cool phenomenon to catch visually.
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022JD03...
https://en.wikipedia.org/wiki/Crown_shyness
https://en.wikipedia.org/wiki/St._Elmo's_fire