Sun exposure in the trunk

2005/01/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Astronomia

Investigating tree trunks using the carbon 14 technique, they have managed to analyze the activity of the Sun. According to this study, current activity is the highest of the last 8,000 years.

Researchers have joined many fields of science to obtain results. On the one hand, they have used an astrophysics hypothesis: The more intense the activity of the Sun, the less cosmic rays reach the Earth's atmosphere because it repels the magnetic fields of the Sun.

On the other hand, the physics of the molecules of the atmosphere has been taken into account. In short, cosmic rays increase the proportion of 14 carbon isotopes in the carbon dioxide molecules of the atmosphere.

Biology. Through photosynthesis, the trees internalize carbon dioxide and, among other things, accumulate carbon 14 in the rings of the trunk.

Finally, paleontology. Tree fossils have been analyzed to know the carbon content of 14 at the time of growth of the trunks. And as the result of this study reflects all of the above, scientists have been able to relate the rings of tree trunks to solar activity. That is, the fossils of which a great activity developed have little carbon 14.

The method has given very good results, since it confirms the obtained by other methods. Therefore, it is clear that the current solar activity is the highest of the last 8,000 years.