Photodissociation in the atmosphere
Although the integrated energy in UV rays and X rays emitted from the Sun represents less than 10 percent of the total energy that the Sun sends in our direction, its interaction with the Earth’s atmosphere is considerable.
Photodissociation is a process in which a photon from the Sun fragments an atmospheric atom or molecule into new atomic or molecular components.
Photodissociation plays a very important role in the chemistry of planetary atmospheres, including the atmospheric chemistry here on Earth.
Photoionization in the atmosphere
The Sun’s radiation also causes photoionisation:
Photoionization is a process in which a photon ejects one or more electrons from a neutral atmospheric particle (atom or molecule) turning it into a charged particle - an ion.