Posted by Donald Boon on December 05, 2003 at 07:22:53:
All Solar proton activity continues low, and solar electrons dipped as a solar wind generated a mild geomagnetic storm. Earthquake activity remains below 6M. Trudy Day from ECTV posted a comment on the NASA article on Pinpoint just before the Digest went to press, and I did not see her comments until this morning. She points out that the author is a science journalist, and not a research scientist. She then adds the following interesting note, which I have abbreviated:[quote] ...a team of geo-physicists from Finland and Germany..have calculated that the Sun is more magnetically active now than it has been for over a 1000 years. They say their technique, which relies on a radioactive dating technique, is the first direct quantitative reconstruction of solar activity based on physical, rather than statistical, models (I G Usoskin et al. 2003 Phys. Rev. Lett. 91 211101) Sunspots are produced by magnetic activity inside the Sun. The more active the Sun is, the more spots are produced. Observations of sunspots began in 1610 - soon after the telescope was invented - and no other directly obtained data exists from before this time.
Now, Usoskin and co-workers have used the concentration of beryllium-10 in polar ice as a proxy for historic levels of solar activity. Beryllium-10 is produced when cosmic rays interact with particles in the Earth's atmosphere. The radioisotope then falls to the ground where it is stored in layers of ice. The Sun's magnetic field can deflect cosmic rays away from the Earth, so a stronger field should lead to less beryllium-10 being produced, and vice versa. Using modeling techniques, the Finnish team was able to extend data on solar activity back to 850 AD. The researchers found that there has been a sharp increase in the number of sunspots since the beginning of the 20th century. They calculated that the average number was about 30 per year between 850 and 1900, and then increased to 60 between 1900 and 1944, and is now at its highest ever value of 76. [/quote] So even if the NASA article is science journalism, it is important. On the other hand, are we just watching another solar cycle? Donald
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