After
months of relative quietude, a trio of new sunspot groups appeared this week
and they are all growing rapidly.
But
there's something strange about these spots.
Sunspots
are cool regions of intense, twisted magnetic activity at the solar surface.
They act like caps on the upwelling of energy, and when the caps pop, flares of
radiation and ejections of charged particles are unleashed. Major solar storms
can disrupt communications on Earth and even disable satellites.
The
sun goes through an 11-year cycle of activity. The last peak, when sunspots
were common and flares frequent, was in 2001 and 2002. The new cycle, Solar
Cycle 24, began recently, scientists figure, based on a sunspot with reversed
polarity appearing. But pinning down exactly when the shift occurred has proven
challenging — it might have been in 2006,
sun-watching scientists reported initially, or perhaps 2007,
they later said.
Adding
to the tangle of understanding, the new sunspots have a magnetic polarity
consistent with Solar Cycle 23 rather than the new cycle, proving yet again
that much remains to be learned about the temperamental
sun.
One
of the new sunspots, No. 989, kicked up a moderate solar flare Tuesday. NOAA
forecasters put the odds at 50-50 for additional moderate flares today.
Solar
storms sometimes generate colorful
auroras above Earth's polar regions. No significant auroral displays are
expected this week, however.
Though
forecasts
vary wildly, some scientists predict Solar Cycle 24 will be intense. If so,
"it could have significant impacts on telecommunications, air traffic,
power grids and GPS systems," according to a NASA statement issued in
December.
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