Solar Cycle Progression
First published: 2015
Brief summary
NOAA/NASA solar cycle monitoring and sunspot progression data.
Article
The solar cycle is the recurring variation in solar magnetic activity observed through sunspots, solar radio emission, flares and other indicators. Sunspot numbers generally rise from a minimum to a maximum and then decline over an average interval of about eleven years, although individual cycles vary in length and strength.
The NOAA Solar Cycle Progression product tracks observed and smoothed sunspot numbers together with the 10.7-centimetre solar radio flux. These measurements provide complementary indicators of activity in the Sun’s photosphere and upper atmosphere.
The plots compare recent observations with predicted ranges produced for the current cycle. Monthly values fluctuate substantially, so smoothed series are used to show the underlying progression from minimum through maximum and toward the next minimum.
Solar-cycle monitoring supports space-weather planning because stronger activity increases the likelihood of solar flares, coronal mass ejections and energetic-particle events. The cycle describes a broad statistical progression rather than a precise schedule for individual eruptions.
Source details and credits
- Source / publisher: NOAA SWPC
- Source type: Data portal
- URL type: WWW
- Credits: NOAA SWPC
- URL: https://www.swpc.noaa.gov/products/solar-cycle-progression