What Causes Lightning? The Answer Keeps Getting More Interesting. (Quanta, 5/6)

[eppur_se_muova]

2. Bear in mind ... cloud chambers were one of the ways cosmic rays were originally discovered.

Cloud chambers and spark-gap chambers are routinely used to study subatomic particles here on Earth. In both devices, the passage of high-energy particles through a sub-critical medium leaves a trail of ionized particles in its wake, which then leads to visible changes of condensation or electrical discharge. If portions of our atmosphere are teetering on the edge of electrical breakdown, why wouldn't we expect to see cosmic rays induce lightning, at least occasionally ? The big question is now: how often ?