This /end thread There is no reasonable way to harvest antimatter from life or weather processes. The only way to do so now is in the lab, which scientists are getting better at. I imagine one day future people might be able to construct massively huge particle accelerators in solar orbit to provide anti-matter for spaceflight, and medical uses, etc (I am hoping we're past the interest in developing annihilation weapons but I'm cynical enough to think those will be made as well). if that ends up being more useful for travel than fusion, solar-sail, magsail, whatever. Who knows what practicable uses for it people will have in the future? What if antimatter behaves very differently, or oppositely when it comes to gravity? That alone could generate some extremely interesting uses. So there is a need for antimatter, but as interesting as lightening discharges generating a bit of it might be, hard to imagine its more than a scientific curiosity. It would be interesting to eventually find if Venusian lightening, which is very different from Earth lightening due to the lack of water vapor, also emits positrons.
Harvesting antimatter? Nigh impossible, the stuff you're after would be anti hydrogen, that stuff has antiprotons which would instantly destroy every other equal amount of matter if it came into contact with it.. one oops and you'll lose the stuff and damage your container...
Back around 1980, I had an electrical engineering professor who was part of a team that detected naturally-occurring antimatter high in the atmosphere using a balloon-lofted detector. (Probably from cosmic rays hitting the atmosphere.) For about a week, he was a minor international celebrity, being interviewed by the science press around the world. It was pretty cool, seeing how excited he was. He was a really good professor; I enjoyed his class.
here is a link of interest http://www.walterjonwilliams.net/2011/01/duct-tape-now-less-awesome/ I think some superbolts may trail off into blue jets. https://www.sciencedaily.com/releases/2019/09/190909113041.htm https://www.sciencedaily.com/releases/2008/03/080328102738.htm Now, I wonder if this power might be harvested in some way--as these may generate more anti-matter than normal bolts. The largest lightning strokes are in Jupiter
I had typed a reply that I wasn't even sure I remembered his name correctly, but stopped to do a search. I found his obituary from the American Astronomical Society at a Harvard site. Robert L Golden, of New Mexico State University. Director of the Particle Astrophysics Laboratory, who also taught electrical engineering classes. His team discovered anti-protons from galactic cosmic radiation in 1979. He did a lot of other cool stuff, like serving in numerous NASA advisory groups, that I was completely unaware of as a freshman taking a class with him. There weren't any links there to papers he might have written, but a more in-depth search using the info from the obit might yield something, if you wanted to.