A grand solar minimum can occur when the “solar magnetism diminishes, sunspots appear infrequently and less ultraviolet radiation reaches Earth,” according to NASA.                      The sun is a stormy brew of electrically charged gases that generates a magnetic field on a roughly 11-year cycle. The 11-year sunspot cycles are caused by the sun’s rotation in space, according to NASA. As the star rotates roughly once every 27 days, its material acts like a fluid, so that its equator rotates much faster than its poles do. Sunspots and solar flares rise and fall every 11 years, a cycle associated with regular reversal of the star’s magnetic field.

LEARNING WITH TIMES AND BASICS

                     The Sun is made of hot ionised plasma whose motions generate magnetic fields in the solar interior by harnessing the energy of the plasma flows. This mechanism is known as the solar dynamo mechanism . Simply stated, it is a process by which kinetic energy of plasma motions is converted to magnetic energy, which generates the magnetised sunspots, giving rise to the solar cycle.

Because of the nature of the solar dynamo, the part of its magnetic field that gives rise to sunspots reverses direction when it moves from one solar cycle to another. This can be inferred by observing when the relative orientation of the sunspot pairs flip. The sun’s change in polarity causes its magnetic activity — and its sunspots — to eventually die down, resulting in a solar minimum. But the sun’s rotating magnetic field slowly gets tangled again, and the sunspot cycle begins anew.

Sunspots are the origins of solar outbursts like coronal mass ejections and flares, which hurl radiation and charged particles across the solar system. Visible sunspots are caused by magnetic disturbances in the sun that displace its bright outer layer and reveal the slightly cooler (and darker) interior layers, usually for a few days but sometimes for several weeks. Sunspots are cooler regions in the photosphere of the sun and have deep magnetic fields surrounding them.

EFFECTS ON EARTH’S ATMOSPHERE

              When many sunspots are visible, the Sun is somewhat brighter than in “quiet” times and radiates considerably more in the ultraviolet. On the other hand, the cosmic ray intensity entering the Earth’s atmosphere varies opposite to the solar activity, since the cosmic ray particles are deflected by the Sun’s magnetic field to a greater or lesser degree. With increased solar activity (and stronger magnetic fields), the cosmic ray intensity decreases, and with it the amount of cloud coverage, resulting in a rise of temperatures on Earth. Conversely, a reduction in solar activity produces lower temperature.

These powerful solar storms can be bad for us here on Earth, as the powerful energy from flares and protons can play havoc on our modern electronic world. So far, astronomers have documented 24 such cycles, the last one ended in 2019.