New ‘sun clock’ quantifies extreme space weather switch on/off

Extreme space weather events can significantly impact systems such as satellites, communications systems, power distribution and aviation. They are driven by solar activity which is known to have an irregular but roughly 11 year cycle. By devising a new, regular ‘sun clock’, researchers have found that the switch on and off of periods of high solar activity is quite sharp, and are able to determine the switch on/off times.