Solar cycle 22

Solar cycle 22
The Sun, with some sunspots visible, during solar cycle 22 (1992).
Sunspot Data
Start date	September 1986
End date	May 1996
Duration (years)	9.7
Max count	158.5
Max count month	July 1989
Min count	8.0
Spotless days	309
Cycle chronology
Previous cycle	Solar cycle 21 (1976-1986)
Next cycle	Solar cycle 23 (1996-2008)

Solar cycle 22 was the 22nd solar cycle since 1755, when extensive recording of solar sunspot activity began. 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. 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.

During March 1989, a severe 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. A few days before, on March 6, 1989, a very large X15 solar flare also occurred. 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. 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.

As midnight came and went, invisible electromagnetic forces were staging their own pitched battle in a vast arena bounded by the sky above and the rocky subterranean reaches of the Earth. A river of charged particles and electrons in the ionosphere flowed from west to east, inducing powerful electrical currents in the ground that surged into many natural nooks and crannies.