Solar Irradiation Variability

The large planets affects irradiation variability from the sun.

My interest in the subject dates back to the defense of my doctor thesis in 2004. I was asked to elaborate on the expected global warming influence on marine eco systems in the Barents Sea. The task was solved by a study a Greenland data series, which showed temperature samples since the year 555. In this data series I found stationary periods showed minimum temperature in the 1800s and a new minimum around 2040.

A minimum of 1800 figure was no surprise. But what happened in the 1800s, which started the development of a warmer climate? A development that has lasted until today. Meanwhile, there was reason to believe that the stationary periods will continue in the years ahead. The question was then, can we expect a new deep cold period, similar to what we had in the 1700s? A new deep minimum temperature period will have a major consequences for energy and food production on Earth.

Cause of causes

The work on this article has roots back in spring 2014, when I met Jan- Erik Solheim and others at University of Oslo. Here I told them about my analysis of data series from Greenland, and the question whether there is an underlying cause of climate change. A Cause of causes. The question was not accidental. The Cause of cause is a term from Aristotle, which relate to the sun and planetary periods.

The research question was therefore whether there is something predictable in radiation from the sun. If we can not find something deterministic in radiation from the sun, we can only explain the past, and no computer can predict future solar variability. One can then neither can say anything with certainty about future climate on Earth. Then Jan-Erik and I started to look for a possible stationary Cause of causes, which eventually became to this article in New Astronomy. A work that lasted for more than two years .

The research

The activity of the sun has been linked to counting sunspots, discovered by Galileo Galilei. Solar scientists have been studying sunspots since the 1700s. Data series for sunspots therefore represents one of the world's longest continuous data series. There has been a prevailing opinion that there is a correlation between sunspots and climate periods. How this relationship really is, has been unclear. In my doctoral work, I found no traces of sunspots in data series of climate indicators. My students have not found such a correlation, when they learned to analyze data series. I was therefore skeptical about the idea of ​​sunspots as climate indicators. But the relationship eventually came forward after the data series for Total Solar Irradiation (TSI) was analyzed. Then it turned out that TSI and sunspots was rooted in Uranus's period of 84 years, and that there was a correlation between TSI solar radiation and sunspots for periods of about 210 years. This confirmed for the first time a long-term relationship between sunspots and solar radiation.

Data series for TSI also had its challenges. Direct measurement of radiation from the sun started first in 1978. The data series backward to the year 1700 and the year 1000 is based on estimates from inter alia ice samples (10Be and 14C). Furthermore there provided multiple data series with slightly different weighting of estimates. All data series were therefore analysed. Results showed that all had the same periods but somewhat different amplitude. It was then decided to use the longest two data series that was based a physical estimate representation of radiation.

The reference for a stationary period in the data series, was that a stationary period also should have a known stationary source, a Cause of causes. The choice was the oscillating solar system. In the solar system there is a mutual gravity between the planets and the sun, causing the sun's position to oscillate around a virtual point. Data series for sun oscillation around this point was chosen as reference for planetary oscillations around the sun, and as a reference for an identification of stationary periods in the data series. The stationary periods in the data series were identified with a new method to study wavelet specter data series. It turned out that this method was very accurate and confirmed at the same time the quality of the data series.


  • Deterministic periods: Data series of total radiation (TSI) from the sun, has stationary periodic changes over 1000 years.
  • Cause: The periods are controlled by the four giant planets: Jupiter, Saturn, Uranus and Neptune.
  • Explanation: There is a mutual gravitation between the sun and the planets that change circulation in Sun's interior dynamo.
  • Harmonic periods: Planets periods and combination resonance between periods produces a range of stationary periods from about 11 to 500 years, and more
  • Impact: The sum of the period affects the sun's surface and alter the radiation from the sun and climate on Earth.
  • Historic Climate Change: The identified periods explains known cold climate periods Oort (1010-1030), Wolf (1270-1349), Spurs (1390-1550), Maunder (1640-1720) and Dalton (1790-1820)
  • Modern climate: We have had a modern maximum period (1940-2015) with radiation.
  • Prognosis: We are entering a period with less radiation, a "colder" sunny, with a calculated at a minimum of Dalton-level of approximately (2040-2065).

Further work

The article provides a basis for further work within the themes :
- A New Perspective on the sun's inner dynamo
- Developing better models calculating the historical and expected future radiation from the sun
- A better understanding of current and future climate change on Earth


Journal: Yndestad H, Solheim, JE; (2016) New Astronomy 51 (2017) 135–152

Presentation: EGU-2016, 20.04.16. Viena. 

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