Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online.Space weather is the concept of changing environmental conditions in near-Earth space. It is distinct from the concept of weather within a planetary atmosphere, and deals with phenomena involving ambient plasma, magnetic fields, radiation and other matter in space. "Space weather" often implicitly means the conditions in near-Earth space within the magnetosphere, but it is also studied in interplanetary (and occasionally interstellar) space. Within our own solar system, space weather is greatly influenced by the speed and density of the solar wind and the interplanetary magnetic field (IMF) carried by the solar wind plasma. A variety of physical phenomena are associated with space weather, including geomagnetic storms and substorms, energization of the Van Allen radiation belts, ionospheric disturbances and scintillation, aurora and geomagnetically induced currents at Earth''s surface.