August 21, 2009

Sunspots fading away

Not only are the sunspot numbers declining, it seems that the magnetic strength of each spot is declining precipitously as well. From SpaceWeather:
ARE SUNSPOTS DISAPPEARING?
Sunspots are made of magnetism. The "firmament" of a sunspot is not matter but rather a strong magnetic field that appears dark because it blocks the upflow of heat from the sun's fiery depths. Without magnetism, there would be no sunspots.

That's what makes the following graph a little troubling:
sunspot_mag_fields.jpg

According to Bill Livingston and Matt Penn of the National Solar Observatory in Tucson, Arizona, sunspot magnetic fields are waning. The two respected solar astronomers have been measuring solar magnetism since 1992. Their technique is based on Zeeman splitting of infrared spectral lines emitted by iron atoms in the vicinity of sunspots. Extrapolating their data into the future suggests that sunspots could completely disappear within decades. That would be a bummer for Spaceweather.com.

Don't count out sunspots just yet, however. While the data of Livingston and Penn are widely thought to be correct, far-reaching extrapolations may be premature. This type of measurement is relatively new, and the data reaches back less than 17 years. "Whether this is an omen of long-term sunspot decline, analogous to the Maunder Minimum, remains to be seen," they caution in a recent EOS article.

One thing is certain. Solar Minimum is a lot more interesting than it sounds: more.
This is going to make food prices very interesting in the next five years if this is what I think it is. Time to look into an equatorial bolt-hole... Posted by DaveH at August 21, 2009 11:02 PM
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