The Cycles of the Sun
By Bruce Scofield
(originally published in Llewellyn’s Moon Sign Book 2003)
We owe our lives to our Sun. In fact, almost all life on Earth is fueled by the Sun. The Sun radiates energy that simple organisms feed on, and more complex organisms, such as ourselves, feed on them. The one exception to this rule are the organisms that live deep in the oceans around volcanic vents. These creatures use the heat energy of the Earth to keep them going. But it could be argued that this heat is really the remnants of the energy released by the proto-Sun billions of years ago when the solar system was formed. Ultimately, energy must come from somewhere, and for us, it's the Sun.
The Sun has several cycles that scientists have observed and measured. First, the Sun rotates once every 25 days, but just at its equator. The regions above and below the solar equator rotate more slowly, about 27 days. This is possible because the Sun is not solid; it's plasma. Solar rotation is an important solar cycle and one that affects the solar wind, as we will see below. A second important solar cycle is the sunspot cycle. Sunspots are large disturbed, stormy areas on the Sun, so large in fact, that many, many Earths could be placed over a large one before it becomes obstructed. They are intensely magnetic and made of elongated filament-like structures. Sunspots appear dark because they slow down the heat radiating outwards from the Sun's interior. The number of sunspots on the Sun at any given time varies over a roughly 11-year cycle. This cycle has many implications for conditions on Earth, and of interest to astrologers, it may be driven by the motions of the planets.
The Solar Wind
The Sun is the closest star. When we look at it, what we see is the solar atmosphere, the first layer of which is called the photosphere. It's from this region of the Sun that solar radiation (including light) escapes and ultimately "feeds" the Earth. Above the photosphere is the chromosphere. This layer of the Sun's atmosphere is less dense and its gases are transparent - they do not emit light. The chromosphere is observable during a solar eclipse when the main disk of the Sun is blocked by the Moon. Beyond this layer is the corona, also observed most clearly during an eclipse. This "crown-like" part of the solar atmosphere extends well out into space and gradually thins into the solar wind that flows out into the solar system.
The solar wind is a stream of charged gas particles, mostly hydrogen, that are lost from the Sun. The solar wind is essentially very rarified gas, so thinned out that there are only two particles of the gas in each cubic centimeter. But it is very, very hot - in the neighborhood of 200,000 degrees Kelvin. As the solar wind extends from the Sun's corona, it moves through the solar system, passing the planets. Because the Sun rotates, the solar wind radiates out from the Sun like streams of water from a rotating lawn sprinkler. The solar wind also carries with it magnetic fields that spiral out into the solar system, creating what is called the Interplanetary Magnetic Field or IMF. If the Earth or another planet just happens to be in the way of one of these spiraling waves of magnetically charged solar wind, it gets blasted.
The charge particles of the solar wind blow right into the Earth's own magnetic field, bending it like the bow of a ship bends the water in front of it. When the solar wind is particularly active, like right after a solar flare occurs, its collision with the Earth's magnetic field is more intense. This is what creates the aurora borealis, better known as the northern lights.
When the Sun is very active, coronal mass ejections (CMEs) occur. These are massive magnetic gas bubbles that are ejected from the Sun and disrupt the flow of the solar wind. Solar flares and prominence eruptions are other violent solar phenomena that can occur in conjunction with CMEs. Particles from flares and CMEs can cause major disturbances on Earth. Radio communications are disrupted, satellites can be damaged, and passengers in high-altitude airplanes may be subjected to radiation comparable to that of a medical X-ray. The frequency of CMEs is related to the sunspot cycle (see below) and their intensity varies. When the cycle is at minimum, about one CME per week is observed. Near solar maximum the number is more like two or three per day.
Sunspots and the Solar Cycle
The sunspot cycle measures the frequency of dark spots on the sun. Galileo was one of the first to notice these "blemishes" when he trained his telescope on the Sun some 400 years ago. He thought they were clouds in the Sun's atmosphere. Besides discovering the spots themselves, he also discovered that the Sun rotates. He came to this conclusion by recognizing that the number of sunspots and their location on the Sun changes daily. Over a sequence of days, Galileo had observed specific sunspots moving across the face of the Sun, which strongly suggested solar rotation.
By the middle of the 19th century, astronomers had determined that there was a sunspot cycle of 11 years (on average) during which the number of sunspots changes from a minimum to a maximum. It had also been determined that over the course of the sunspot cycle, the region where the spots form on the Sun shifts. Spot formation begins well above and below the Sun's equator but as the cycle progresses they move towards the equator. What all this means to us will be explained later. For now, keep in mind that the sunspot cycle is a key solar cycle, that it tracks the number of sunspots that exist on the Sun over a period of time, and that this period averages about 11 years.
The sunspot cycle is not only the best known of the solar cycles, but its correlations with other cycles are of special interest. First of all, the cycle of the Sun's brightness, or total energy output, is linked to this cycle. The Sun is brightest when sunspots are at their maximum. It does seem strange that the Sun would be brighter at precisely the time that it is most covered with dark spots, but it is. When the Sun is brighter, it is emitting more energy. The sunspot cycle is a way to measure the Sun's total energy output. Why should we be concerned about this? It affects our climate.
I've already stated that the sunspot cycle averages about 11.1 years, but actually it can vary from as little as seven years to as many as seventeen. Further, the number of sunspots in each sunspot cycle vary. Between 1640 and 1720 there was a lull in the number of sunspots - even though records were being kept, none were reported. This period was a major low of solar magnetic activity, and guess what? The overall temperature of the Earth declined by about 1 degree Centigrade. While this doesn't sound like much, it is substantial enough to affect climate. This period has even been named the "Little Ice Age," and the testimonies of those who lived through it in Europe and North America speak of some very cold winters. Rivers froze where they never did before, glaciers grew larger, and crops failed to grow as they used to.
In contrast, the last 50 years of the 20th century have seen very high levels of energy from the Sun, and consequently we are experiencing a warming. For many years this fact has kept many scientists from stating categorically that global warming as the result of fossil fuel burning was occurring. However, since 2000, most agree that the global warming we are experiencing is a combination of both. While it is getting warmer because the Sun is putting out more energy, this is nothing like what happened in the 11th and 12th centuries. Back then the global temperature was up a degree or so. Scandinavia had become a comfortable place to live. People were growing grapes in England. Vikings sailed to Greenland and set up colonies there that lasted for several hundred years, but they collapsed when global temperatures dropped in the 13th century.
The "Little Ice Age" and other world climate variations have been verified in ways other than sunspot counts and eye-witness accounts. Normally, the Earth is bombarded by cosmic rays from outer space, but during the peak of a sunspot cycle these rays are deflected. This inhibits or slows down the formation of Carbon-14 in plants. Therefore, carbon dating can describe the history of energy coming from the Sun. This method of dating does point to the period between 1640 and 1720 as being very different from what came before it and after it. Carbon dating studies have also shown that there are larger solar cycles that affect life on the planet, cycles of 80-90 years, a 200-year cycle, and even one of about 2,200 years.
Forecasting Sunspots
The number of sunspots on the Sun at any given time is a good indication of how active and energizing the Sun is. At the high point of a sunspot cycle, when the Sun is very active, the push of the solar wind on the Earth's magnetic field is strong. There is evidence that suggests this impact affects life on Earth, causing disruptions and excitability. Low sunspot numbers indicate the reverse. Each sunspot cycle differs from the previous one, not only in terms of the number of spots, but also in length. Predicting the exact peak or trough of the cycle is difficult as it can range from 7 to 17 years, though the average is 11.1. Readers interested in following the solar sunspot cycle may wish to visit www.spaceweather.com, one of NASAs web sites, or http://dxlc.com/solar/. On these sites are articles, graphs, and links that may be of interest. Below is a listing of 20th century sunspot cycles.
Sunspot Minimum Years: 1901, 1913, 1923, 1933, 1944, 1954, 1964, 1976, 1986, 1996
Sunspot Maximum Years: 1907, 1918, 1928, 1938, 1948, 1958, 1970, 1980, 1990, 2000/2001
One of the ways that we know the sunspot cycle has reached maximum is by the reversing of the Sun's magnetic field. Every 11 or so years, the Sun's magnetic poles flip; that is, the north and south poles reverse. The solar magnetic poles are much like those of a bar magnet, the magnetic energy flows from each end, or pole, and loops back into its opposite. At sunspot maximum, the combined effects of numerous magnetically charged sunspots is apparently enough to upset the status quo, and the poles reverse. The most recent reversal of the poles was in February of 2001. This change is not limited to the Sun; it extends out into space, carried by the solar wind where it is subjected to all the twists and turns produced by the Sun's rotation. The extended solar magnetic field, called the heliosphere, makes a complex, corkscrew-like pattern that envelopes the planets of the solar system.
Predicting sunspot maximum is not difficult once the cycle has been running for about three years from minimum. But forecasting the nature of the entire cycle has kept scientists busy. Their predictions have not been too impressive. For example, the most recent maximum was predicted for 2000, but at the time of this writing (October 2001), the sunspot numbers are still higher than during most of 2000. The best methods used by scientists analyze the cycle during the minimum, take into account the nature of the previous cycle, and extrapolate into the next one. One of the most reliable techniques has been to note changes in the Earth's magnetic field just before and at sunspot minimum. These are called "geomagnetic precursor" techniques, which basically analyze correlations between fluctuations and sunspots. The currently established, scientifically acceptable methods do not seek any extra-solar causes for the sunspot cycle.
There is, however, a long history of considering planetary influences on solar cycles. Galileo was the first to suggest such a possible explanation, and there was much research on this during the 19th and early 20th century. Most of this work is ignored by modern scientists, but there is one body of alternative research that is worth reporting. By the middle of the 20th century, the radio industry recognized that strong solar events could disrupt radio communications taking place on the side of the Earth facing the Sun. One radio company, RCA, realized it could manage its communication network more efficiently if these disturbing events could be predicted. Around 1950, one of RCA's radio engineers, John Nelson, perfected a method for forecasting disturbances by considering the influence of the planets on the Sun. Using the positions of the planets as indicators of solar activity, his techniques resembled astrology. First, he charted the planets on a grid that looked very much like an astrological chart; then, he tried to locate times when the planetary positions formed alignments with each other. When they did, he would predict a solar storm, and his forecasts proved to be up to 90% accurate. Nelson's heliocentric planetary alignment maps were so similar to astrological horoscopes, and his interpretive skills comparable to those of practicing astrologers, that for many years Nelson was a welcome speaker at astrology conferences.
What Nelson found was that sunspots were usually (but not always) associated with geo-magnetic storms and that certain planetary angles would predict such conditions. Disturbances would occur when the planets were in conjunction (0 degrees), square (90 degrees), or opposition (180 degrees) to each other. These are, of course, the "hard" aspects in astrology. He also found that solar weather was quieter when planets were connected by trines (120 degrees). This aspect is known to astrologers as a favorable and "soft" aspect. Nelson noticed other more subtle angular separations which produce solar activity, those based on multiples of 15 degrees and 18 degrees.
Nelson's work with planetary aspects and sunspots was the work of a seasoned engineer. Others have not been as successful in forecasting radio storms in this manner. Burl Payne has also researched possible connections between planetary alignments and sunspots, and he found that only some planetary conjunctions correlated with increased solar activity; other conjunctions did not. Heliocentric conjunctions between the Earth and Jupiter or Uranus were coincident with peak sunspot numbers while conjunctions involving Mercury and Earth showed a dramatic decrease in numbers. However, Mercury-Earth conjunctions correlated with an increase in storms in the Earth's magnetic field. Venus and the Earth in conjunction seemed to show an initial increase in sunspot numbers, then a decrease. Payne also draws attention to the fact that the counting of sunspots can only account for those that are visible to the Earth. Sunspots on the far side of the Sun may form during planetary alignments, but we won't see them until the Sun rotates them into view. And since the Sun's revolution takes 25 days, changes can occur within this period.
More recent work done by astronomer Percy Seymour has shown that there is a correlation between peaks of solar activity and the peaks of the combined tidal effects on the Sun that are generated by the Earth, Venus, and Jupiter. In other words, these particular planets can combine to form tides on the Sun, and these tides make the Sun active. He has proposed a theory of magneto-tidal resonance which states that the pull of two or more planets moving together around the Sun will pull the plasma of the Sun (just as the Moon pulls the oceans of the Earth, creating the ocean tides). However, their combined effect is much greater than the simple sum of their gravitational influence. Like Nelson, Seymour is suggesting that the aspect theory of the ancient astrologers is not incredible at all; it has simply not been measured quantitatively - until recently.
If you look closely at the listing of sunspot maximums and minimums given above, you will notice that there is not a neat symmetry between these highs and lows. In recent years, it has only taken three or four years from a sunspot minimum to reach a maximum, and this is not half of 11. Although the cycle length averages a little over 11 years, the actual length is not consistent. What may be going on here is that the Sun is responding to the gravitational pull of the giant planets Jupiter and Saturn. While the Sun responds to alignments between each of these planets and the other planets in the solar system, it responds even more strongly when these two are in conjunction or opposition. For example, Jupiter and Saturn were in conjunction in 1980 and 2000, both big years for sunspots. But because there are other planets in the solar system that have their own gravitational contribution, the pull of the planets on the Sun, and the consequent solar activity, is not so easy to predict. In addition to alignments, another factor is perihelion - how close a planet is to the Sun. Nelson was a master of solar activity prediction and learned how to take into account a wide range of planetary influences - just as an astrologer does when reading a chart.
Solar Effects on the Earth
The Sun may have something to do with earthquakes. We know that planetary positions relative to the Sun can affect the Sun, causing it to be more active or passive. When the Sun is active, the solar wind pushing against the Earth's magnetic field can, in turn, cause changes in the circulation of the Earth's upper atmosphere. This, in turn, can cause the Earth to slow its rotation a very small amount. This change in spin rate has been found to correlate with changes in seismic activity. Theoretically, when the Sun is active and causing the solar wind to blow strongly against the Earth, the normal rate of Earth rotation is altered and earthquakes are more likely to occur. Also, solar activity affects global temperature, which in turn affects the amount of ice or water on Earth. Changes in the weight of water/ice can result in increased pressure leading to seismic activity. The North American continent is still "rebounding" from the release of heavy ice sheets of the last Ice Age. Solar activity also affects changes in atmospheric pressure, which acts the same way as water/ice - the sudden release of millions of tons of air pressure can cause the Earth to rebound.
There are probably many other processes on Earth that are affected by the Sun. Most organisms are very responsive to magnetic fields. The nervous system is essentially electro-magnetic in design and in certain cases has evolved to take into consideration the magnetic field of the Earth. For example, it is known that many birds can navigate by using the Earth's magnetic field. Considering that the Earth's magnetic field is itself susceptible to the solar wind, it is very possible that solar storms stimulate the nervous systems of certain life forms on our planet, and not necessarily in positive ways. It appears that the Earth-Sun relationship in regard to magnetism is quite complex and needs to be understood as a system, not as two separate phenomena. There is much to be learned about the Sun, life, and magnetism which might someday turn out to be concrete evidence for the validity of astrology.
References
Baliunas, Sallie and Willie Soon. The Sun-Climate Connection. Sky and Telescope. December 1996.
Brant, John C. New Horizons in Astronomy. San Francisco, CA: W. H. Freeman & Co. 1972.
Hodge, Paul W. Concepts of Contemporary Astronomy. New York: McGraw-Hill. 1974.
NASA: www.spaceweather.com
Nelson, John. Forecasting Magnetic Storms. The Journal of Geocosmic Research. Summer 1974.
Payne, Burl. Planetary Positions and Sunspots. NCGR Journal, Winter 1992-1993.
Seymour, Percy. Cosmic Magnetism. Boston: Adam Hilger. 1986.
Seymour, Percy, M. Willmott, and A. Turner. Sunspots, Planetary Alignments and Solar Magnetism: A Progress Review. Vistas in Astronomy. Vol. 35, 1992.
Vaughan, Valerie. Earth Cycles: The Geocosmic Evidence for Natural Astrology. Amherst, MA: One Reed Publications. 2002.