Solar cycle · ~0.1% over a cycle
Solar Irradiance Variation
The total energy the Sun radiates varies slightly over the activity cycle — by about a tenth of a percent between solar maximum and minimum — as dark sunspots and bright faculae come and go. Measured continuously from space since the late 1970s, these variations are a key input to studies of the Sun's influence on climate.
Highlights
- ›Total output changes ~0.1% across the cycle
The Sun, its layers & phenomena
Knowledge connections
- Associated withThe Sun
- Associated withThe Solar Cycle
- Associated withSunspots
- Associated withPlage
Sources
The primary and reference sources this topic draws on.
- NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.