A sunspot is an area of highly organized magnetic activity on the sun's surface.
From the upi.com
Aurora frequencies are vastly increased whenever there is high sunspot activity.
From the washingtonpost.com
This may sound a bit strange, but the cycle I have in mind is the sunspot cycle.
From the npr.org
The activity is highly unusual because the 11-year sunspot cycle peaked in 2000.
From the newscientist.com
At its lowest ebb, sunspot activity was about 0.1% of normal for some 30 years.
From the time.com
This is where the reduction in sunspot activity makes global temperatures cooler.
From the thisisbristol.co.uk
Accidents happen and who knows what a sunspot can do to all the fragile clouds.
From the guardian.co.uk
Sunspot levels were near their cyclical peak when the FCC reallocated FM in 1945.
From the en.wikipedia.org
This corresponds to a dropping off in sunspot activity in the past few years.
From the economist.com
More examples
A cooler darker spot appearing periodically on the sun's photosphere; associated with a strong magnetic field
Sunspots are temporary phenomena on the photosphere of the Sun that appear visibly as dark spots compared to surrounding regions. They are caused by intense magnetic activity, which inhibits convection, forming areas of reduced surface temperature. ...
Sunspot (Roberto "Bobby" da Costa) is a fictional character, a Marvel Comics superhero most commonly associated with X-Men-related groups the New Mutants and X-Force.
In economics, the term sunspots (or sometimes "a sunspot") usually refers to an extrinsic random variable, that is, a random variable that does not directly affect economic fundamentals (such as endowments, preferences, or technology). ...
The 2010 Transformers toy line by Hasbro (Takara Tomy in Japan under the moniker Transformers: Autobot Alliance) is a continuation of the ' . The film, and thus the toy line, is based on the original Transformers media franchise. This line is accompanied by an online web game on Transformers. ...
(Sunspots) A dark area, which is strongly magnetic, that occurs in the area of the photosphere on the disk of the sun. [Science; v262; 1372-3; 1993.]
(Sunspots) Dark patches on the Sun's surface, exhibiting powerful magnetic fields. They are dark due to having a lower temperature than their brighter surroundings. Sunspots generally appear in groups and can be relatively small (300 km diameter), with larger examples stretching over 100,000 km. ...
(Sunspots) Dark regions on the Sun which are the centers of large vortices and possess powerful magnetic fields. Maximum sunspot activity occurs in cycles with a period of about 11 years.
(Sunspots) Relatively cool regions in the solar photosphere that appear dark. They contain intense magnetic fields which provide the energy for solar flares. Sunspots occur in groups. They underlie plage areas.