Deciphering Solar Magnetic Activity: The Solar Cycle Clock

The Sun’s variability is controlled by the progression and interaction of magnetized systems that form 22-year magnetic activity cycle (the “Hale Cycle”) as they march from their origin at ?55° latitude to equator, over ?19 years. We will discuss end point progression, dubbed “terminator” events, our means diagnosing them. In this paper we expand on Extended Solar Cycle framework construct a new solar “clock” which maps all onto single normalized epoch based terminations Hale Magnetic Cycles. Defining phase 0*2 ? clock Terminators, then polar field reversals occur ? 0.2*2 , geomagnetically quiet intervals centered around minimum start 0.6*2 terminator, thus lasting 40% length. At onset quiescence, “pre-terminator,” Sun shows radical reduction in active region complexity and, like terminator associated with time when radio flux crosses F10.7 = 90 sfu. use terminator-based illustrate range phenomena further emphasize strong global-scale Cycle: vast majority, 96%, X-flares happen between Terminator pre-Terminator. addition X-rays violent flares, rapid changes number energetic photons—EUV spectral emission hot corona flux—impinging atmosphere are predictable Terminator-normalized unit cycle, has implications for improving fidelity atmospheric modelling.