Solar cycle 12 was the twelfth
solar cycle
The solar cycle, also known as the solar magnetic activity cycle, sunspot cycle, or Schwabe cycle, is a nearly periodic 11-year change in the Sun's activity measured in terms of variations in the number of observed sunspots on the Sun's surfa ...
since 1755, when extensive recording of solar
sunspot
Sunspots are phenomena on the Sun's photosphere that appear as temporary spots that are darker than the surrounding areas. They are regions of reduced surface temperature caused by concentrations of magnetic flux that inhibit convection. Sun ...
activity began.
The solar cycle lasted 11.3 years, beginning in December 1878 and ending in March 1890. The maximum
smoothed sunspot number
The Wolf number (also known as the relative sunspot number or Zürich number) is a quantity that measures the number of sunspots and groups of sunspots present on the surface of the Sun.
History
Astronomers have been observing the Sun recordi ...
observed during the solar cycle was 124.4 (December 1883), and the starting minimum was 3.7.
[SIDC Monthly Smoothed Sunspot Number.]
During the minimum transit from solar cycle 12 to 13, there were a total of 736 days with no sunspots.
[Spotless Days.]
[Solaemon's Spotless Days Page.]
1882
A very bright blood-red aurora display happened over New York on 16 April 1882, while significant communication disturbances occurred.
A
geomagnetic storm
A geomagnetic storm, also known as a magnetic storm, is a temporary disturbance of the Earth's magnetosphere caused by a solar wind shock wave and/or cloud of magnetic field that interacts with the Earth's magnetic field.
The disturbance that d ...
later in that year produced the
aurora of November 17, 1882.
See also
*
List of solar cycles Solar cycles are nearly periodic 11-year changes in the Sun's activity that are based on the number of sunspots present on the Sun's surface. The first solar cycle conventionally is said to start in 1755 when Rudolf Wolf began extensive reporting o ...
References
Solar cycles
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