3 Sep 09 – (Excerpts) – “The sun is in the pits of the deepest solar
minimum in nearly a century. Weeks and sometimes whole months go by
without even a single tiny sunspot. The quiet has dragged out for more
than two years, prompting some observers to wonder, are sunspots
disappearing?
"Personally, I'm betting that sunspots are coming back," says
researcher Matt Penn of the National Solar Observatory (NSO) in Tucson,
Arizona. But, he allows, "there is some evidence that they won't."
Penn's colleague Bill Livingston of the NSO has been measuring the
magnetic fields of sunspots for the past 17 years, and he has found a
remarkable trend. Sunspot magnetism is on the decline:
"Sunspot magnetic fields are dropping by about 50 gauss per year," says
Penn. "If we extrapolate this trend into the future, sunspots could
completely vanish around the year 2015."
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| Above: Sunspot magnetic fields
measured by Livingston and Penn from 1992 - Feb. 2009 using an
infrared Zeeman splitting technique. [more] |
“If sunspots do go away, it wouldn't be the first time. In the 17th
century, the sun plunged into a 70-year period of spotlessness known as
the Maunder Minimum that still baffles scientists. The sunspot drought
began in 1645 and lasted until 1715; during that time, some of the best
astronomers in history (e.g., Cassini) monitored the sun and failed to
count more than a few dozen sunspots per year, compared to the usual
thousands.
"Whether [the current downturn] is an omen of long-term sunspot decline,
analogous to the Maunder Minimum, remains to be seen," Livingston and
Penn caution in a recent issue of EOS. "Other indications of solar
activity suggest that sunspots must return in earnest within the next
year."
The Maunder Minimum occurred during the depths of the
Little Ice Age.
I don’t think
that was a coincidence.
See entire article:
http://science.nasa.gov/headlines/y2009/03sep_sunspots.htm?friend
Thanks to Icewoman and Chuck Clancy for this link
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