The study of the changing conditions in the near-Earth space that affect the Earth and the technological systems is broadly known as Space Weather. This includes the study of the Sun and its magnetic field variations giving rise to solar flares and other solar activities, the heliosphere and the study of the Earth's atmosphere and magnetosphere. The spectacular polar aurorae, geomagnetic storms and ionospheric disturbances and scintillation are a few manifestations of Space Weather. Studies of these phenomena, the comets and the zodiacal lights unveiled the existence of solar wind in the 1950s and established its controlling influence on these phenomena. It was also established that the interaction of the solar wind with the magnetosphere produces geomagnetically induced currents (GIC) at Earth's surface and causes massive failures of power grids, corrotion of pipelines, disrups radio and wireless communications. The higly ionized and energetic particles in the solar wind can cause damages to satellites and is life threatening to astronauts.
Here is a list of major events that costed billions of dollars in damages to the technological systems on Earth and space.
- 13 March, 1989: Collapse of HydroQuebec power network, caused by GIC, started by a transformer failure, leading to a general blackout, lasted for more than 9 hours and affected 6 million people. The gepmagnetic storm was caused by a CME on March 9, 1989.
- January 10, 1997: A CME on January 7, 1997 reached the magnetosphere caused the loss of the AT & T Telstar 401 communication satellite of value 200M.
- August 7, 1972: Between Apollo 16 and Apollo 17 a Solar Energetic Particle (SEP) event occurred which if happened during one these missions, would have costed lives if hit the astronauts.
- April 21, 2002: Nozomi Mars Probe was hit by a large SEP causing large-scale failure. The mission, already three years behind schedule, was eventually abandoned in December 2003.
- 1979: The Fire department in Orange County, CA, received a distress signal from a downed commuter plane. When they responded but discovered that the signal originated from an accident site in West Virginia (Lanzerotti, 2000) [*]. 1979 was the peak of solar cycle 21.
Solar radio bursts can interfere with communications in the frequency range 245 MHz to 2.7 GHz, which is widely in use. An analysis of 40 years of solar radio bursts data carried out at Bell Labs revealed some interesting results that led to a statistical interpretation of their potential for disruption in wireless communications: Noise in Wireless Systems Produced by Solar Radio Bursts.
[*] Lanzerotti, L. J., 2000: Space weather effects on communications, An overview of historical and comtemporary impacts of the solar and geospce environments on communications systems, in NATO Science Series, Space Storms and Space Weather Hazards, edited by I. A. Daglis, Proceedings of the NATO Advanced Study Institute on Space Storms and Space Weather Hazards, Hersonissons, Crete, Greece, 19-29 June 2000.