It is followed by ionospheric hole (should be It was... holes)
A ~900km wide patch of the ion blanket around the earth became thinner. Probably in the density sense, not the size sense: there was less plasma there than normal. (The abstract measures this in terms of how many electrons they counted in that area.)
due to rapid chemical reactions of rocket exhaust plumes and ionospheric plasma.
They think the thin patch was caused because the Falcon's exhaust reacted with the ion blanket. I'm not sure how.
I'm curious about this too. The Falcon burns RP-1, essentially a very refined kerosene, with liquid oxygen. Exhaust should be water, carbon dioxide, and a bit of carbon monoxide.
Not typically the most reactive things, but perhaps there are different interactions with plasma?
Anything is reactive when interacting with plasma.
There should be little of those gases naturally up there (mostly so for water), and even throwing a large mass of gases up there may be enough to disturb everything.
This other paper [0] seems to indicate that TEC (total electron count) fluctuations are caused by shock waves, not rapid chemical reactions, and can arise from ground explosions as well. IANA ionosphere scientist, so I don't know if the parent paper made a mistake.
A ~900km wide patch of the ion blanket around the earth became thinner. Probably in the density sense, not the size sense: there was less plasma there than normal. (The abstract measures this in terms of how many electrons they counted in that area.)
due to rapid chemical reactions of rocket exhaust plumes and ionospheric plasma.
They think the thin patch was caused because the Falcon's exhaust reacted with the ion blanket. I'm not sure how.