ARLA/CLUSTER: As manchas solares estão em extinção e desapareceram rapidamente...?

João Gonçalves Costa joao.a.costa ctt.pt
Segunda-Feira, 31 de Agosto de 2009 - 12:16:17 WEST


[http://tbn2.google.com/images?q=tbn:DUNaa9xgg_YJvM:http://www.viewzone.com/sunspot.empty.jpg]<http://www.viewzone.com/sunspot.empty.jpg>
Two astronomers predict sunspots will soon disappear completely

Are sunspots disappearing for good? Two solar researchers say this is the case.

Amateur Radio Newsline's Norm Seeley, KI7UP, has more:

Most hams users know that there is a direct correlation between sunspots and high frequency propagation conditions. In general, the more sunspots there are, the more DX you will be able to work. This usually happens in
11 year cycles with the last solar maximum having taken place in 2000.

The current Solar Cycle which is Cycle 24 should peak in roughly next year in 2010. Only one problem. There have been few sunspots this year and very little easy to work DX. And now there may be an answer as to why.

Spaceweather.com reports that astronomers Bill Livingston and Matt Penn of the National Solar Observatory in Tucson, Arizona, have found that sunspot magnetic fields are definitely waning. Not only that. They say that sunspots could completely disappear within decades.

Livingston and Penn have been measuring solar magnetism since 1992. Their technique is based on a complex system called the Zeeman splitting of infrared spectral lines emitted by iron atoms in the vicinity of sunspots. They reached their conclusion by extrapolating their already collected data into the future.

But Spaceweather also says not to count out sunspots just yet. It notes that while the data of Livingston and Penn is widely thought to be correct, that any far reaching extrapolations may be premature. It says that this type of measurement is relatively new, and the data reaches back less than 17 years. In the end it appears as if the giant solar disk we call the sun is the only one who holds the answers to the future of its spots and how good DX will be in the coming years.



Norm Seeley, KI7UP
Amateur Radio Newsline.



And a bit of an astro physics lesson before we leave this story. For those not aware, sunspots are made of magnetism. In other words a sunspot is not matter but rather a strong magnetic field that appears dark because it
blocks the upward flow of heat from the sun's fiery depths. Spaceweather says that without magnetism, there would be no sunspots.
(Spaceweather, others
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