The solar cycle is the cycle that the Sun’s magnetic field goes through approximately every 11 years.
Solar minima and maxima are the two extremes of the Sun's 11-year activity cycle.
Solar Minimum
Solar minimum is the period of least solar activity in the 11-year solar cycle of the Sun.
During this time, sunspot and solar flare activity diminishes, and often does not occur for days at a time.
Solar minima are correlated with changes in climate.
The most infamous Solar Minimum happened between 1645 to 1715, termed as “Maunder Minimum” - when sunspots were very rare for an extended period.
Solar Maximum
During solar maximum, large numbers of sunspots appear, and the solar irradiance output grows tremendously.
At solar maximum, the Sun's magnetic field lines are the most distorted due to the magnetic field on the solar equator rotating at a slightly faster pace than at the solar poles.
Large solar flares occur during a maximum.
What is a sunspot?
It’s an area of intense magnetic activity on the surface of the Sun—a storm—that appears as an area of darkness.
Sunspots are indicative of solar activity, giving birth to solar flares and coronal mass ejections (CMEs).
Sunspots have been continuously counted each day since 1838.
This has allowed solar scientists to describe a repeating pattern in the wax and wane of activity on the Sun’s surface—the solar cycle.
How does the solar cycle affect Earth?
The more charged-up the solar wind headed towards Earth, the brighter and more frequent are the displays of Northern Lights and Southern Light (Aurora)
For example, the solar storm of 1859 struck the Earth with such intensity that the northern lights were visible as far from the poles as Cuba and Hawaii.
Power outages, satellite malfunctions, communication disruptions, and GPS receiver malfunctions are other few things that can happen during a solar maximum.