Zharkova uses solar-planetary theory in new paper predicting Earth temperature rise to 2600 following imminent Grand Solar Minimum

An important new solar paper by Prof Valentina Zharkova and co-authors S. J. Shepherd, S. I. Zharkov & E. Popova  published in ‘Nature’ has incorporated the solar-planetary theory we’ve been researching and advancing here at the talkshop over the last decade. As well as further developing her previous double dynamo theory which now accounts for the last several millennium’s solar grand minima and maxima, she includes discussion of Fairbridge, Mackey, Shirley, Charvatova and Abreu et al’s work. Central to the new hypothesis is the motion of the Sun around the barycentre of the solar system, described as the Solar Inertial Motion [SIM].

Left plot: the example of SIM trajectories of the Sun about the barycenter calculated from 1950 until 2100³⁴. Right plot: the cone of expanding SIM orbits of the Sun³⁵ with the top showing 2D orbit projections similar to the left plot. Here there are three complete SIM orbits of the Sun, each of which takes about 179 years. Each solar orbit consists of about eight, 22-year solar cycles³⁵. The total time span is, therefore, three 179-year solar cycles³¹, or about 600 years. Source: Adapted from Mackey³⁵. Reproduced with permission from the Coastal Education and Research Foundation, Inc

Following my discussion with her at dinner following her talk in London last year, Zharkova now agrees with us that the SIM induced by planetary motion affects sunspot production and solar activity levels.

However, in the light of newly discovered double dynamo effects in the solar interior⁶ the planets can surely perturb properties of the solar interior governing the solar dynamo in the outer layer, such as solar differential rotation, or Ω-effect, governing migration of a magnetic flux through the outer layer to its surface, and those of α effect, that can change the velocity of meridional circulation. This leads to the dynamo waves in this outer layer with the frequency slightly different from that than in the inner layer, and, thus to the beating effects caused by interference of these two waves and to grand cycles discussed above⁶.

In addition, Zharkova discusses the effect of SIM on the Sun-Earth distance observed by Shirley and develops the theme to account for differential warming of Earth’s hemispheres and the planet as a whole over long time periods. An observed anomaly which confounds the mainstream GHG theory of climate change. She characterises the irradiance received at Earth due to this SIM induced variation as the Baseline Magnetic Field.

Top plot: the close-up view of the oscillations of the baseline magnetic field (dark blue curve) in the current and past millennia with a minimum occurring during Maunder Minimum (MM). The irradiance curve (magenta line) presented from Krivova and Solanki^27,28overplotted on the summary curve of magnetic field (light blue curve)⁶. Note the irradiance curve is slightly reduced in magnitude in the years 0–1400 to avoid messy curves. The dark rectangle indicates the position of MM coinciding with the minimum of the current baseline curve and the minimum of the solar irradiance^27,28. The scale of the baseline variations are shown on the left hand side of Y axis, the scale of the summary curve – on the right hand side. Bottom plot: variations of the Earth temperature for the past 140 years derived by Akasofu²⁶ with the solid dark line showing the baseline increase of the temperature, blue and red areas show natural oscillations of this temperature caused by combined terrestrial causes and solar activity. The increase of terrestrial temperature is defined by 0.5 °C per 100 years²⁶.

Going into further detail, Zharkova says:

If during SIM the Sun moves closer to perihelion and the spring equinox (positions 2), thus increasing the Earth orbit eccentricity, the distance between the Sun and Earth will be the shortest at perihelion approaching about 1.44 × 10⁸ km while at aphelion it will increase to 1.55 × 10⁸ km. This means at these times the Earth would receive higher than usual solar irradiance (that can lead to higher terrestrial temperatures)^26,43,44, while approaching its perihelion during its winter and spring (warmer winters and springs in the Northern hemisphere and summers and autumns in the Southern one). 

Here are the paper’s conclusions, including predictions for future temperatures in full:

Conclusions:
Until recently, solar activity was accepted to be one of the important factors defining the temperature on Earth and other planets. In this paper we reproduced the summary curve of the solar magnetic field associated with solar activity^5,6 for the one hundred thousand years backward by using the formulas describing the sum of the two principal components found from the full disk solar magnetograms. In the past 3000 years the summary curve shows the solar activity for every 11 years and occurrence of 9 grand solar cycles of 350–400 years, which are caused by the beating effects of two magnetic waves generated by solar dynamo at the inner and outer layers inside the solar interior with close but not equal frequencies⁶.

The resulting summary curve reveals a remarkable resemblance to the sunspot and terrestrial activity reported in the past millennia including the significant grand solar minima: Maunder Minimum (1645–1715), Wolf minimum (1200), Oort minimum (1010–1050), Homer minimum (800–900 BC) combined with the grand solar maxima: the medieval warm period (900–1200), the Roman warm period (400–10BC) etc. It also predicts the upcoming grand solar minimum, similar to Maunder Minimum, which starts in 2020 and will last until 2055.

A reconstruction of solar total irradiance suggests that there is an increase in the cycle-averaged total solar irradiance (TSI) since the Maunder minimum by a value of about 1–1.5 Wm^−2 27. This increase is closely correlated with the similar increase of the average terrestrial temperature^26,43. Moreover, from the summary curve for the past 100 thousand years we found the similar oscillations of the baseline of magnetic field with a period of 1950 ± 95 years (a super-grand solar cycle) by filtering out the large-scale oscillations in 11 year cycles. The last minimum of a super-grand cycle occurred at the beginning of Maunder minimum. Currently, the baseline magnetic field (and solar irradiance) are increasing to reach its maximum at 2600, after which the baseline magnetic field become decreasing for another 1000 years.

The oscillations of the baseline of solar magnetic field are likely to be caused by the solar inertial motion about the barycentre of the solar system caused by large planets. This, in turn, is closely linked to an increase of solar irradiance caused by the positions of the Sun either closer to aphelion and autumn equinox or perihelion and spring equinox. Therefore, the oscillations of the baseline define the global trend of solar magnetic field and solar irradiance over a period of about 2100 years. In the current millennium since Maunder minimum we have the increase of the baseline magnetic field and solar irradiance for another 580 years. This increase leads to the terrestrial temperature increase as noted by Akasofu²⁶ during the past two hundred years. Based on the growth rate of 0.5 C per 100 years²⁶ for the terrestrial temperature since Maunder minimum, one can anticipate that the increase of the solar baseline magnetic field expected to occur up to 2600 because of SIM will lead, in turn, to the increase of the terrestrial baseline temperature since MM by 1.3 °C (in 2100) and, at least, by 2.5–3.0 °C (in 2600).

Naturally, on top of this increase of the baseline terrestrial temperature, there are imposed much larger temperature oscillations caused by standard solar activity cycles of 11 and 350–400 years and terrestrial causes. The terrestrial temperature is expected to grow during maxima of 11 year solar cycles and to decrease during their minima. Furthermore, the substantial temperature decreases are expected during the two grand minima⁴⁷ to occur in 2020–2055 and 2370–2415⁶, whose magnitudes cannot be yet predicted and need further investigation. These oscillations of the estimated terrestrial temperature do not include any human-induced factors, which were outside the scope of the current paper.

The paper is currently open access, so grab a copy now!