This discovery of double dynamo action in the Sun brought us a timely warning about the upcoming grand solar minimum 1, when solar magnetic field and its magnetic activity will be reduced by 70%. This period has started in the Sun in 2020 and will last until 2053. During this modern grand minimum, one would expect to see a reduction of the average terrestrial temperature by up to 1.0°C, especially, during the periods of solar minima between the cycles 25–26 and 26–27, e.g. in the decade 2031–2043.
Valentina Zharkova, Modern Grand Solar Minimum Will lead to terrestrial cooling , in Temperature, 4 August 2020
My take on it
If you had never heard of a Grand Solar Minimum before today, I am not far ahead of you. A colleague kept mentioning it, in the context of energy generation, so I thought I best take a closer look.
Providential perhaps, that in my first browse on the topic I should come across this article, read it, appreciate the evident competence of the author, and glean some of the core information I was seeking.
Valentina Zharkova is a Professor in Mathematics at Northumbria University. She obtained her PhD from the Solar Division of the Main Astronomical Observatory, Kyiv, Ukraine and her thesis was in non-LTE radiative transfer entitled “Hydrogen emission in quiescent solar prominences with filamentary structure”. She has been a Lecturer at the University of Bradford, and in 2002 she appointed to a Reader and in 2005 to a Professor in Applied Mathematics. From September 2013 she joined the Northumbria University as a Professor in Mathematics.
My takeways are these:
The sun is the main source of energy for all planets of the solar system.
This energy is delivered to Earth in a form of solar radiation in different wavelengths, called total solar irradiance.
Solar irradiance varies, due to sunspot activity and related magnetic fields.
Zharkova’s analysis reveals the appearance of Grand Solar Cycles of 350–400 years caused by the interference of two magnetic waves. These grand cycles are separated by the grand solar minima, or the periods of very low solar activity.
The previous grand solar minimum was Maunder minimum (1645–1710), and the one before that, Wolf minimum (1270–1350).
In the next 500 years there are two modern grand solar minima approaching in the Sun: the modern one in the 21st century (2020–2053) and the second one in the 24th century (2370–2415)
During the periods of low solar activity, such as the modern grand solar minimum, the Sun will often be devoid of sunspots.
The reduction of solar magnetic field will cause a decrease of solar irradiance.
“During this modern grand minimum, one would expect to see a reduction of the average terrestrial temperature by up to 1.0°C, especially, during the periods of solar minima between the cycles 25–26 and 26–27, e.g. in the decade 2031–2043.”
“The reduction of a terrestrial temperature during the next 30 years can have important implications for different parts of the planet on growing vegetation, agriculture, food supplies, and heating needs in both Northern and Southern hemispheres. This global cooling during the upcoming grand solar minimum 1 (2020–2053) can offset for three decades any signs of global warming and would require inter-government efforts to tackle problems with heat and food supplies for the whole population of the Earth.