Sunspots are actually the harbingers of magnetic activity on the Sun which
can accelerate particles near the Sun to high energies, and eject them during
flare events and Coronal Mass Ejections (CMEs). It is the CME events, most
common when sunspots are in evidence, which travel to Earth in a few days and
can interfere with the terrestrial plasma environment, causing magnetic
sub-storms, auroral activity, and influence everything from telecommunications
to the electrical power grid. Here is what a CME looks like, thanks to the Solar Heliospheric Observatory located in space.
Also, there seems to be a correlation between years of enhanced solar
activity (heightened sunspot numbers) and the severity of weather systems in
the northern hemisphere. No one really understands what the connection is.
Return to Dr. Odenwald's FAQ page at the Astronomy Cafe Blog.