An air shower is an extensive (many kilometres wide) cascade of ionized particles and electromagnetic radiation produced in the atmosphere when a primary cosmic ray (i.e. one of extraterrestrial origin) enters the atmosphere.
The term cascade means that the incident particle, which could be a proton, a nucleus, an electron, a photon, or (rarely) a positron, strikes an atom’s nucleus in the air so as to produce many energetic hadrons.
The unstable hadrons decay in the air speedily into other particles and electromagnetic radiation, which are part of the shower components.
The secondary radiation rains down, including x-rays, muons, protons, antiprotons, alpha particles, pions, electrons, positrons, and neutrons.
The dose from cosmic radiation is largely from muons, neutrons, and electrons, with a dose rate that varies in different parts of the world and based largely on the geomagnetic field, altitude, and solar cycle.
Airline crews receive more cosmic rays if they routinely work flight routes that take them close to the North or South pole at high altitudes, where this type of radiation is maximal.
The air shower was discovered by Bruno Rossi in 1934. By observing the cosmic ray with the detectors placed apart from each other, Rossi recognized that many particles arrive simultaneously at the detectors.[1] This phenomenon is now called an air shower.
https://en.wikipedia.org/wiki/Air_shower_(physics)
Yeah. I was working with the guys on Mt Hopkins (AZ) back in 71 when they first started building “fly eye’ detectors using milsurp searchlight mirrors & photomultiplier tubes..
Last I was in Delta Ut, I got the tour at the Lon and Mary Watson Cosmic Ray Center. Pretty fun stuff, but as a “worker bee” (vs a starving post doc) I made the choice long ago to skip “grant-funded” projects.
Still, *Coherent* Cherenkov radiation is what makes the air shower phenomenon so...cool.
Still, pretty cool stuff.
BTW - Cherenkov radiation - the glow seen in air showers is the same glow seen in atomic reactors where the neutrons strike a water moderator.
https://arxiv.org/abs/1107.0665