Oscillations of the baseline of solar magnetic field and solar irradiance on a millennial timescale

TL;DR

This paper investigates millennial-scale oscillations in the solar magnetic field and irradiance, revealing long-term cycles and their potential impact on Earth's climate, including a possible future increase in global temperature.

Contribution

It introduces a 100,000-year double dynamo model and identifies a 1950-year super-grand cycle linked to solar inertial motion, advancing understanding of solar-terrestrial interactions.

Findings

Confirmed strong oscillations in solar activity at 11-year and 350-400-year cycles.

Discovered a 1950-year super-grand cycle in baseline magnetic field oscillations.

Linked baseline magnetic field oscillations to potential terrestrial temperature increases.

Abstract

Recently discovered long-term oscillations of the solar background magnetic field associated with double dynamo waves generated in inner and outer layers of the Sun indicate that the solar activity is heading in the next three decades (2019-2055) to a Modern grand minimum similar to Maunder one. On the other hand, a reconstruction of solar total irradiance suggests that since the Maunder minimum there is an increase in the cycle-averaged total solar irradiance (TSI) by a value of about $1-1.5$ $Wm^{-2}$ closely correlated with an increase of the baseline (average) terrestrial temperature. In order to understand these two opposite trends, we calculated the double dynamo summary curve of magnetic field variations backward one hundred thousand years allowing us to confirm strong oscillations of solar activity in regular (11 year) and recently reported grand (350-400 year) solar cycles caused by actions of the double solar dynamo. In addition, oscillations of the baseline (zero-line) of magnetic field with a period of $1950\pm95$ years (a super-grand cycle) are discovered by applying a running averaging filter to suppress large-scale oscillations of 11 year cycles. Latest minimum of the baseline oscillations is found to coincide with the grand solar minimum (the Maunder minimum) occurred before the current super-grand cycle start. Since then the baseline magnitude became slowly increasing towards its maximum at $~$2700 to be followed by its decrease and minimum at $~$3700. These oscillations of the baseline solar magnetic field are found associated with a long-term solar inertial motion about the barycenter of the solar system that can lead to a further natural increase of the terrestrial temperature by 2.5-3.0$^\circ$C.