Cosmic tree ring growth

Russ Steele

The eleven year cycle in grain prices in the British Isles led to the discovery that the 11 year sunspot cycle influenced the earth's climate, thus grain production. Now the Brits have discovered that the growth the growth of British trees appears to follow a cosmic pattern, with trees growing faster when high levels of cosmic radiation arrive from space during periods of low sunspots.

Researchers made the discovery studying how growth rings of spruce trees have varied over the past half a century. As yet, they cannot explain the pattern, but variation in cosmic rays impacted tree growth more than changes in temperature or precipitation. The study is published in the scientific journal New Phytologist.

The full BBC story is here, but let's explore the sun spot connection in the story.

Here comes the Sun

Cosmic rays are actually energetic particles, mainly protons, as well as electrons and the nuclei of helium atoms, that stream through space before hitting the Earth's atmosphere.
The levels of cosmic rays reaching the Earth go up and down according to the activity of the Sun, which follows an 11-year cycle.

Every 11 years or so, the Sun becomes more active, producing a peak of sunspots. These sunspots carry a magnetic field that blocks and slows the path of energetic particles.
When the researchers looked at their data, they found that tree growth was highest during periods of low sunspot activity, when most cosmic rays reached Earth.

But growth slowed during the four periods of cosmic ray-blocking high sunspot activity, which have occurred between 1965 and 2005.

"We tried to correlate the width of the rings, i.e. the growth rate, to climatological factors like temperature. We also thought it would be interesting to look for patterns related to solar activity, as a few people previously have suggested such a link," explains Ms Dengel.

"We found them. And the relation of the rings to the solar cycle was much stronger than it was to any of the climatological factors we had looked at. We were quite hesitant at first, as solar cycles have been a controversial topic in climatology."

"As for the mechanism, we are puzzled." Sigrid Dengel, University of Edinburgh.

There needs to be more scientific investigation, but these preliminary findings seem to lend credence to Svensmark’s work on GCR to cloud cover correlation by demonstrating yet another tangible effect.  Fewer sunspots, more cosmic ray, more cloud cover, a cooler earth. And the sun remains quiet.