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. With the new '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. Once the clock is constructed from sunspot observations it can be used to order observations of solar activity and space weather. All these observations show the same sharp switch on and switch off times of activity.

Source: dna June 11, 2020 16:18 UTC