Interestingly, there are about 100 events of this severity (G4) per cycle, and a single cycle lasts 11 years. This means there are about nine G4 events on average per year.

G4: " Induced pipeline currents affect preventive measures, HF radio propagation sporadic..."

G5: " Pipeline currents can reach hundreds of amps, HF (high frequency) radio propagation may be impossible in many areas for one to two days..."

We are at kp 8.67. The Carrington event was a kp 9

> Biological: Unavoidable radiation hazard to astronauts on EVA; passengers and crew in high-flying aircraft at high latitudes may be exposed to radiation risk.

Anyone have a sense of magnitude for this advisory? How much more radiation should an airline passenger expect to receive during a G4 event than normal?

Looks like we get these for about 60 days for periods lasting 11 years.

so more of a 'bad storm here and there' level?