Science Struck
Science Struck: Ionosphere Facts
Learn facts about the ionosphere. It is an extension of the thermosphere, one of the five layers of the atmosphere.
University of Sydney (Australia)
Ionospheric Physics: Photoionization
Defines photoionization analytically, describing it in terms of formulas. Contains links to other sites related to atmospheric/ionospheric physics.
Science Struck
Science Struck: Facts About the Thermosphere
Learn facts about the thermosphere, one of the five layers of the atmosphere.
NASA
Nasa: Image Science Center: Ask the Space Scientist Earth
Site from NASA contains a collection of 91 questions pertaining to the Earth's atmosphere, magnetic field, ionosphere, rotation and origin of life.
Exploratorium
Exploratorium: Auroras Paintings in the Sky
This site offers a very nice, detailed explanation of auroras along with some inspiring images and videos.