Valentina Zharkova is a Professor in Mathematics at Northumbria University. She specializes in solar physics and has focused on testing low frequency coupled dynamics with atmospheric-terrestrial-oceanic effects.
In the referenced opinion piece, Dr. Zharkova uses newly discovered solar activity proxy -the solar magnetic field – to demonstrate the Sun’s entry into the modern Grand Solar Minimum (2020–2053). The predicted low frequency down-cycle will lead to a significant reduction of solar magnetic field and activity comparable to that experienced during the Maunder minimum. This reduction will likely lead to noticeable reduction of terrestrial temperature.
Sunspot magnetic fields take on a toroidal topology while solar background magnetic field forms a poloidal field.
Applying Principal Component Analysis (PCA) to the low-resolution full disk magnetograms captured in cycles 21–23 by the Wilcox Solar Observatory, Zharkova’s research team discovered two principal components of this solar background magnetic field.
The modulus summary curve obtained from the summary curve are shown in the top plot as a black curve. The bottom plot presents the modulus summary curve associated with the sunspot numbers derived for cycles 21–23.
So what does all of this mean?
Well, first off, let’s put this all in context.
The flagship IPCC GHG model is CMIP5. This model has never passed backtest against history.
One reason for this poor performance is IPCC limited the solar effect to total solar irradiance (TSI). For focusing on TSI, IPCC ignores the solar-terrestrial dynamics associated with the solar magnetic field. Since TSI doesn’t vary much, that assumption leaves only GHG concentration to drive atmospheric warming (and cooling) since 1850.
The problem is there isn’t enough warming coming out of GFG ECS parameter estimates (citations available). Thus, the statistical correlation between warming and GHG concentration is weak. Measurable but not material.
So, something else is driving the observed warming and cooling observed in the HadCRUT4 post-1850 data used in CMIP.
Zharkova argues the missing driver of warming and cooling utilizes both the TSI amplitude of a solar cycle and the leading magnetic polarity of solar magnetic field.
That driver looks like this – cyclical with a periodicity much longer than the 22-year high frequency solar cycle:
What do these low frequency cycles mean?
Well, for one thing, they explain history better than IPCC CMIP5.
“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.
“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.”
Zharkova, V. (2020). Modern Grand Solar Minimum will lead to terrestrial cooling. Temperature (Austin, Tex.), 1–6.