Something unexpected appears to be happening on the sun.
2013 is supposed to be the year of Solar Max also known as
the peak of Cycle 24. Yet 2013 has arrived and solar
activity is relatively low. Sunspot numbers are well below
their values in 2011, and strong solar flares have been
infrequent for many months. The quiet has led some
observers to wonder if forecasters missed the mark.
Dean Pesnell is a Solar physicist at the Goddard Space
Flight Centre in Greenbelt, Maryland. He suggests that this
is the solar maximum, but it looks different from what we
expected because it will be double peaked.
Conventional wisdom holds that solar activity swings back
and forth like a simple pendulum. At one end of the cycle,
there is a quiet time with few sunspots and flares. At the
other end, the Solar Max brings high sunspot numbers and
solar storms with a regular rhythm that repeats every 11
years.
Reality, however, is more complicated. Astronomers have
been counting sunspots for centuries, and they have seen
that the solar cycle is not perfectly regular. For one
thing, the back-and-forth swing in sunspot counts can take
anywhere from 10 to 13 years to complete. Also, the
amplitude of the cycle varies. Some solar maxima are very
weak while others can be very strong.
And as researcher Pesnell notes, there is yet another
complication. He says that the last two solar maxima,
around 1989 and 2001, had not one but two peaks. He says
that solar activity went up, dipped, and then resumed while
performing a mini-cycle within the Solar Max that lasted
about two years.
Pesnell says that the same thing could be happening now. He
notes that sunspot counts jumped in 2011 and dipped in 2012.
As such, he expects them to rebound again saying that
another peak will happen in 2013 and possibly last into
2014. Lets hope he is right.
