Sun

The Sun is the source of ultraviolet (UV) radiation which can be so damaging to life on Earth. Fortunately, the ozone layer protects us and other life forms against the damaging affects of solar rays.

Changes in solar activity can influence naturally the amount of ozone in the stratosphere. Stratospheric ozone is primarily created by ultraviolet (UV) radiation coming from the Sun. The Sun's energy release does vary, especially over the 11-year sunspot cycle. During the active phase of the 11-year sunspot cycle, more ozone is produced in the ozone layer. This phenomenon can boost the average ozone concentration over the poles by about 4%, although the global increase is nearer 2%.

Unusual solar activity can cause the ozone levels in the upper stratosphere to be substantially depleted, but since most of the ozone is in the middle stratosphere, the effect on total stratospheric ozone is negligible.