The Cosmology/Climate Connection - How Extraterrestrial Forces Influence The Weather
The Sun, Moon, planets and stars might ultimately control Earth’s atmosphere and oceans.
Our Dynamic Planet
Earth is NOT an isolated ball, statically situated in a completely vacuous space. It is an active, elastic sphere moving through a cosmic environment rich in astronomical energies. Its atmosphere is a thin, fluid envelope encircling and interacting with a more densely fluid, liquid covering (the oceans). Beyond these terrestrial fluid features, fluid-like cosmic plasma ebbs and flows between the planets and sun, and between the expanses of interstellar space where spectacular events shape all reality, as we know it.
We humans are fortunate to find ourselves in a protective bubble that consistently enables our survival over spans of time that seem great for us, but truthfully are insignificant for the universe. Weather patterns and their longer-term cousins, climate patterns, both enable and disable different life forms, depending on how the elements harmonize. Currently, forces far more powerful and far more long-lived than humans have the final control over these patterns. Any serious discussion of climate, therefore, must take account of the cosmic forces that ultimately prevail over us.
Solar System’s Motion In The Universe
Planet Earth belongs to a planetary system circling around a star known as the Sun. Collectively, the Sun and its planets comprise the Solar system. The Sun is itself a member of a greater system named “The Milky Way”, a disc-shaped, spiral galaxy of two hundred billion stars moving around a galactic center.
Stars in the Milky Way galaxy (including the Sun) move at different speeds around the galactic center and in different displacements above or below the galactic plane :
- Old stars (such as the Sun) have high velocities and can move out of the galactic plane.
- Young stars have low velocities and small displacements from the galactic plane.
- Giant molecular clouds (birthplaces of stars) also have low velocities and stay relatively close to the galactic plane.
Overall, the entire galaxy rotates clockwise (as viewed from “galactic north”) at a roughly constant velocity of 160-220 km/sec:
- Relative to this velocity, the Sun and its planetary system move around the galactic center at a velocity of 17-22 km/sec, in a roughly elliptical orbit, with a period of about 240 million years.
- The Sun and its planetary system also move perpendicular to the galactic plane (up and down in a harmonic fashion) with a period of 57-74 million years.
The Solar system, therefore, has two main components of motion within the Milky Way galaxy:
- a round-and-round motion around the galactic center, and
- an up-and-down motion across the galactic plane,
both taking place simultaneously.
An in-and-out motion (from the galactic center) due to its elliptical orbit also gives the Solar system a third distinctive component of motion in the galaxy. Another way to say all this is that the Sun and its planets spiral through the Milky Way like a corkscrew. [See pictures below]
Even Bigger Cosmic Motions
Not only does the Solar system move around the Milky Way galaxy, but also the Milky Way galaxy moves around the center of a super-cluster of 2,500 neighboring galaxies.
And this super-cluster of 2,500 galaxies (including the Milky Way) is hurtling through space towards a point now known as “The Great Attractor”.
Earth’s Motion In The Solar System
With this picture of the Solar system’s motion in mind, let us focus for a moment on the Earth’s motions within the Solar system, which occur simultaneously with the bigger cosmic motions.
Towering walls of blue ice in a Greenland, drained glacial lake [pictured above] reflect astronomical rhythms that reverberate over millions of years to shape patterns in land, water and air.
A widely accepted theory holds that climate rhythms over the last two million years have occurred primarily because of cyclical changes in Earth’s spin around its own axis and because of cyclical changes in Earth’s orbit around the Sun :
- Every 100,000 years, the eccentricity of Earth’s orbit around the Sun oscillates between 0% and 5%.
- Every 41,000 years, the tilt of Earth’s spin axis oscillates between 21.5° and 24.5°.
- Every 23,000 years, the spatial orientation of Earth’s spin axis oscillates between pointing towards Polaris and pointing towards Vega as the North Star.
These oscillations (often called Milankovitch cycles) result from gravitational forces exerted by the planets. Milankovitch cycles cause alterations both in how much and in what locations solar radiation reaches Earth’s surface, thus producing ice age epochs with intermittent warm ages. Such alterations occur because of distance and angle variations between the Earth and Sun, quite independent of (or in addition to) variations in the Sun’s own energy output.
Click ... HERE ... for Milankovitch Cycles animation.
Planetary And Lunar Tidal Forces
There are further complications. Not only do the Moon, Sun and other planets exert gravitational forces (tidal forces) that cause Milankovitch cycles, but also planetary tidal forces influence the Sunspot cycle . Because a correlation exists between the Sunspot cycle and Earth’s temperature, this correlation implies that planetary tidal forces might be an underlying mechanism influencing Earth’s climate. Furthermore, the Moon’s greater tidal force directly upon the Earth affects the oceans, which, in turn, affects climate (perhaps over millions of years) .
A few decades ago, any suggestion that the Moon played a role in determining global ocean properties was lunatic. Now it seems obvious. Today there is wide agreement that Earth’s tides mix ocean waters from their coldest depths to their warmest surfaces and vice versa. Any realistic model of ocean properties and climate, therefore, must take tidal mixing into account .
Physicist and software developer, Clive Best  has written an informative article for laymen on the possible effects of the Moon’s tidal force on Earth’s climate, where he points out:
- Even though the Sun’s heating (especially in the tropics) drives Earth’s weather by causing huge convection cells, the Moon’s tidal force also has a subtle effect on the atmosphere by producing small, regular pressure changes and winds.
- Another effect is the precession of the lunar orbit over a timescale of about 18 years, which changes the inclination of the Moon in the sky, moving Earth’s tidal bulge to a more or less northerly position.
- Growing evidence indicates that the Moon can influence generations of storms and rainfall, although separating this effect from the influence of Sunspots is not universally accepted.
The Sun’s Effect On Climate
The Sun seems to play a far greater direct role in Earth’s climate than many people previously thought , :
- Changes in total solar irradiance provide variable heat input to the lower atmosphere.
- Changes in solar ultraviolet radiation and its interaction with ozone in the stratosphere connect dynamically to the lower atmosphere.
- Changes in solar-modulated cosmic ray flux affect cloud processes, thunderstorm electrification and thermodynamics, and ice formation in cyclones.
Of particular interest is the effect of cosmic rays emitted both by the Sun itself and by the Milky Way galaxy as a whole. The Sun radiates these high-energy particles, as well as modulates their influx from the rest of the galaxy via Solar wind shielding.
There is the further complexity of Earth’s own slowly changing geomagnetic field, which also modulates cosmic ray flux. Cosmic ray flux is precisely what some scientists believe influences the abundance of cloud condensation nuclei, which influences the amount of cloud cover cooling the Earth.
In a paper published in 2008, Ilya Usoskin and Gennady Kovaltsov  conclude:
“cosmic rays seem to be a plausible climate driver, as supported by the bulk of statistical studies and existing theoretical models. Although each individual piece of evidence is barely significant, in aggregate, all the pieces of evidence suggest that the relation between cosmic rays and climate change is real.”
Cosmic rays, however, are not the end of the Sun-climate connection. There is another Solar effect.
Solar Inertial Motion
Many people picture the Sun as a stationary star with respect to its orbiting planets. Space scientists know otherwise :
- The Sun moves continually around the center of mass of the Solar system—the barycenter—inside a circular area about two Sun diameters in size.
- Unlike the planets’ orbits around the Solar system’s barycenter, the Sun’s barycentric orbit differs greatly from orbit to orbit.
As Richard Macky describes it:
“At one phase, the orbit is nearly circular, almost two solar diameters in diameter. At another phase, the Sun is impelled on a backward, or retrograde, journey in which it undergoes a tight loop-the-loop, crossing over its own path in a loop that is less than one solar radius.”
This motion is illustrated in the diagram below for the period of years, 1923-1944 (left), and for the period of years, 1968-2013 (right).
- No two Solar barycentric orbits are the same, and no alignment of the planets in relation to the Sun repeats itself exactly.
- The Sun’s barycentric orbit, as well as its spin around its own axis, in addition to resonant effects between the planets, collectively strengthen or weaken the turning power of the planets. This, in turn, amplifies the resonant effect between the Sun’s barycentric orbit and Sun’s axial spin.
Consequently, the Solar system is chaotic, containing intrinsic randomness. Earth’s climate, therefore, might well follow this dynamic, non-linear, stochastic and unpredictably periodic interaction between the mass of the Sun shifting internally and the planets.
A more sophisticated picture of Earth’s tides now comes into view as well, where the Earth and Moon no longer stand in an independent, two-point relationship. Instead, an Earth-Moon ensemble orbits their own barycenter, experiencing the perturbing effects of the Sun, Earth and Moon jointly orbiting the Solar system’s barycenter.
. . . a tangled web of possible climatic effects, indeed!
But we are still not finished.
Remember The Big Picture
Remember that the Sun, Earth, Moon and other planets (with their moons) are moving around the Milky Way galaxy, which is moving through the vast expanses of interstellar space. How might these motions affect Earth’s climate?
According to H. Svensmark :
- Accepted theory holds that spiral arms are density waves in which stars and gas of the entire galaxy are participating. The Solar system passes through dense and less dense regions associated with these spiral arms, both in its elliptical orbit around the galactic center and in its perpendicular oscillation above and below the galactic plane.
- During its vertical oscillation, the Solar system likely encounters a higher flux of cosmic rays in the Galactic plane than at a maximum distance from the Galactic plane. Earth’s climate, therefore, is likely colder in the Galactic plane than at a maximum distance from the Galactic plane.
- Many studies now demonstrate a remarkable correlation between cosmic ray variations and climate variations. These studies suggest that cosmic ray ionization is influencing the Earth’s climate.
- A construction of the cosmic ray flux over the entire 4.6 billion-year history of the solar system correlates well with the known climate history of the Earth. Although cosmic rays are not the only influence on climate, they seem to have a significant effect on Earth’s climate.
A. V. Sankaran  contributes additional insight:
- The Milky Way galaxy has a spiral-armed structure of four main arms, each orbiting the galactic centre at a different velocity. These arms, consisting of stars in various stages of formation and decay, exhibit strong magnetic fields.
- A number of researchers interpret major climatic changes over millions of years (including the great global ice ages) as Earth’s responses to various galactic forces that act on the sun and planets in orbit around the galactic center.
- When the solar system passes through the galaxy’s spiral arms, it encounters a flux of high-energy particles generated by the birth and death of stars (essentially protons). Between spiral arms, these particles remain confined by strong galactic magnetic fields, so Earth encounters an increased flux of these particles. The interplanetary and planetary magnetic fields of the Solar system modulate the severity of this flux, which influences cloud formation, global temperature reduction and the onset of ice ages.
- Variable acceleration of Earth’s rotation, during and between passages through the spiral arms, is also responsible for changes in Earth’s magnetic fields, which influences atmospheric physics.
A 2006 comprehensive summary of the evidence by K. Scherer  and coauthors points out strengths and weaknesses in the arguments for such influences. [see REFERENCES for a link]
In a more recent study, Coryn Bailer-Jones  considers the following list of possible extraterrestrial climatic influences:
- Asteroid or comet impacts that cause dust and sulfates to cool the globe or even eject the atmosphere.
- Supernova and gamma ray bursts that release large amounts of energy in the form of hard x-rays or cosmic rays, which ionize the atmosphere, destroy the ozone layer and change atmospheric chemistry to absorb visible Solar radiation, thereby cooling the planet.
- Solar system’s encounter with giant molecular clouds that inject cosmic dust into Earth’s atmosphere, lowering Solar irradiation and cooling the planet or concomitantly fueling the Sun, raising its luminosity, and increasing Earth’s precipitation, which triggers an ice age.
- Solar system’s crossing the galactic spiral arms, exposes it to greater cosmic ray flux.
- Solar system’s crossing the galactic plane, which exposing Earth to greater cosmic ray flux.
- Solar system’s radial motion with respect to the galactic center.
- Sun’s varying electromagnetic flux and cosmic ray flux in the solar wind, which mediates galactic cosmic ray flux, controls cloud formation and cools the planet.
- Variations in Earth’s orbit about the Sun.
For periods of ½ to 3 million years, possible extraterrestrial influences on Earth’s temperature are:
- natural solar variability,
- variation in the eccentricity or inclination of Earth’s orbit,
- variation in the orientation of Earth’s spin axis.
For periods of 10 to hundreds of millions of years, possible extraterrestrial influences on Earth’s climate are:
- sun/solar system crossing the galactic spiral-arms,
- sun/solar system crossing the galactic plane,
- sun/solar system encountering giant molecular clouds.
Bailer-Jones concludes that the strength of the evidence for these influences is not very strong. He uses a very strict standard of proof.
I suspect that his strict standard of proof would also disqualify the so-called “consensus” that CO2 drives global temperature rise. In this respect, he gives a sobering piece of advice:
“…there are choices to be made in data analysis. It is not as objective as it sometimes appears to be. Time series analysis is a complicated business: there are decisions of which data to include, what preprocessing to do, which methods to use and which significance tests to apply. We should question the assumptions and identify the uncertainties in order to examine what impact they have on potentially far-reaching conclusions.”
In another critical perspective, Andrew Overholt  and coauthors specifically address the issue of the Solar system’s passage through the Milky Way’s spiral arms. They conclude that newer models of the spiral arms cannot produce correlations with climate change that older models of the spiral arms produced, thus disqualifying the connection. Reading these authors’ paper raises the question (in my mind), “Are scientists in a position to accurately determine the most far-reaching cosmic effects on Earth’s climate?” I sense that they are not.
The search for climate cycles is alluring. But single, periodic causes with simple periodic effects might not be reality in a fluid dynamic universe. Perhaps multiple, coincident, non-periodic causes produce similar effects. And creative chaos is the only rule.
1. Paul R. Weissman, The Solar System and Its Place in the Galaxy, [in Encyclopedia of the Solar system]
2. Matt Beedle (1999), Milankovitch Cycles [website of a web project on glaciers and glacial geology at Montana State Universtiy, no longer online].
3. I. R. G. Wilson (2008), Do Periodic Peaks In The Planetary Tidal Forces Acting Upon The Sun Influence The Sunspot Cycle
4. Walter Munk, Mathew Dzieciuch and Steven Jayne (15 February 2002), Millennial Climate Variability: Is There A Tidal Connection, JOURNAL OF CLIMATE, vol 15, p 370-385
5. Walter Munk and Bruce Bills (February 2007), Tides And The Climate: Some Speculations, JOURNAL OF PHYSICAL OCEANOGRAPHY, vol 37, p 135-147
6. Clive Best (2009), Does The Moon Effect The Earth’s Climate [blog web page]
7. S. Fred Singer and Craig Idso (2009), Chapter 5 – Solar Variability And Climate Cycles, CLIMATE CHANGE RECONSIDERED, p 207-279
8. K.Lassen (?), Long-Term Variations In Solar Activity And Their Apparent Effect On The Earth's Climate, THE MILLENNIUM GROUP [website]
9. Ilya G. Usoskin and Gennady A. Kovaltsov (January 2008), Cosmic
Rays And Climate Of The Earth: Possible Connection, COMPTES RENDUS GEOSCIENCE, 340: p 441-450
10. Richard Mackey (2007), Rhodes Fairbridge And The Idea That The Solar System Regulates The Earth’s Climate, JOURNAL OF COASTAL RESEARCH, SI 50 (Proceedings of the 9th International Symposium), p 955-968
11. H. Svensmark (16 October 2006), Imprint Of Galactic Dynamics On Earth’s Climate, Center for Sun Climate Research, Danish National Space Center
12. A. V. Sankaran (25 September 2008), Galactic Triggers of Geologic Events In Earth’s History, Current Science, vol 95, no 6, p 714-716
13. K. Scherer, H. Fichtner, T. Borrmann, J. Beer, L. Desorgher, E. Flu¨ Kiger, H.-J. Fahr, S. E. S. Ferreira, U. W. Langer, M. S. Potgieter, B. Heber, J. Masarik, N. J. Shaviv and J. Veizer (20 November 2006), Interstellar-Terrestrial Relations: Variable Cosmic Environments, The Dynamic Heliosphere, And Their Imprints On Terrestrial Archives And Climate, SPACE SCIENCE REVIEWS, 127: 327–465
14. Coryn A.L. Bailer-Jones (23 June 2009), The Evidence For And Against Astronomical Impacts On Climate Change And Mass Extinctions: A Review, INTERNATIONAL JOURNAL OF ASTROBIOLOGY
15. Andrew C. Overholt, Adrian L. Melott, and Martin Pohl (2009), Testing The Link Between Terrestrial Climate Change And Galactic Spiral Arm Transit, ARXIV.ORG