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How is the radiation divided when the Sun varies?

The eruptive events, though extremely energetic and potentially hazardous, are very short-lived and thus have a minor effect on the overall radiation from the Sun. Sunspots and faculae, though localized, have a measurable impact on the overall radiation at the Earth. If we compare the radiation coming from the Sun, at all wavelengths, at times when the magnetic field structures are weakest - the so-called solar minimum - with the times of solar maximum, then we see that the magnitudes of the variations differ substantially with wavelength. Even though the total variation (all wavelengths combined) is 0.1%, in certain regions of the ultraviolet wavelengths, the variations are up to 100%! It is the variations in these wavelengths which are crucial to an understanding of how certain chemical species (e.g., ozone) vary in response to changing solar activity.

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Approved by Peter Fox
Last revised: Wed May 17 11:28:21 MDT 2000