Sunspots & Flares

  • Regions of magnetic disturbance on the surface of the sun
  • Activity reaches a maximum in 11 year cycles;  level of ionisation follows this cycle
  • Exceptional long-distance signal paths on higher frequencies at the maximum of the cycle
  • Severe sunspot disturbances (Flares) cause rapid fluctuations of the ionised layers often producing radio blackouts
  • Solar Flux (solar noise measured at UHF) is used as an indicator of solar activity