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Solar cycle 22 was the 22nd solar cycle since 1755, when extensive recording of solar sunspot activity began.〔Kane, R.P. (2002). "(Some Implications Using the Group Sunspot Number Reconstruction )". ''Solar Physics'' 205(2), 383-401.〕〔(【引用サイトリンク】 url=http://www.spacetoday.org/SolSys/Sun/Sunspots.html )〕 The solar cycle lasted 9.7 years, beginning in September 1986 and ending in May 1996. The maximum smoothed sunspot number (monthly number of sunspots averaged over a twelve-month period) observed during the solar cycle was 158.5 (July 1989), and the minimum was 8.〔SIDC Monthly Smoothed Sunspot Number. "()"〕 The maximum is identical with that of solar cycle 3, making it the equal third highest peak on record. There were a total of 309 days with no sunspots during this cycle.〔Spotless Days. "()"〕〔What's Wrong with the Sun? (Nothing) more information: Spotless Days. "()"〕〔Solaemon's Spotless Days Page. "()"〕 ==March 1989 geomagnetic storm== (詳細はgeomagnetic storm caused the collapse of Hydro-Québec's electricity transmission system. The geomagnetic storm causing this event was itself the result of a Coronal Mass Ejection on March 9, 1989.〔. (Geomagnetic Storms Can Threaten Electric Power Grid ) ''Earth in Space'', Vol. 9, No. 7, March 1997, pp.9-11 (American Geophysical Union)〕 A few days before, on March 6, 1989, a very large X15 solar flare also occurred.〔http://sohowww.nascom.nasa.gov/hotshots/X17/〕 At 2:44 am on March 13, 1989, a severe geomagnetic storm struck Earth. The storm began on Earth with extremely intense auroras at the poles. The aurora could be seen as far south as Texas.〔 As this occurred during the Cold War, many worried that a nuclear first-strike might be in progress.〔(【引用サイトリンク】title=A Conflagration of Storms )〕 Others considered the intense auroras to be associated with the Space Shuttle mission STS-29, which had been launched on March 13 at 9:57:00 AM. The burst caused short-wave radio interference, including the disruption of radio signals from Radio Free Europe into Russia. It was initially believed that the signals had been jammed by the Soviet government.
Some satellites in polar orbits lost control for several hours. GOES weather satellite communications were interrupted causing weather images to be lost. NASA's TDRS-1 communication satellite recorded over 250 anomalies caused by the increased particles flowing into its sensitive electronics.〔 The Space Shuttle Discovery was having its own mysterious problems. A sensor on one of the tanks supplying hydrogen to a fuel cell was showing unusually high pressure readings on March 13. The problem went away just as mysteriously after the solar storm subsided. The variations in the earth's magnetic field also tripped circuit breakers on Hydro-Québec's power grid. The utility's very long transmission lines and the fact that most of Quebec sits on a large rock shield prevented current flowing through the earth, finding a less resistant path along the 735 kV power lines.〔(【引用サイトリンク】title=Electricity in nature - March 1989 ) 〕 The James Bay network went offline in less than 90 seconds, giving Quebec its second massive blackout in 11 months. The power failure lasted 9 hours and forced the company to implement various mitigation strategies, including raising the trip level, installing series compensation on ultra high voltage lines and upgrading various monitoring and operational procedures. Other utilities in North America, the UK, Northern Europe and elsewhere implemented programs to reduce the risks associated with geomagnetically induced currents.〔 Since 1995, geomagnetic storms and solar flares have been monitored from the Solar and Heliospheric Observatory (SOHO) joint-NASA-European Space Agency satellite. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Solar cycle 22」の詳細全文を読む スポンサード リンク
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