I'm teaching Astronomy again this summer, though it isn't something I do
every semester. I'm wondering about the following quote from Kaufmann and
Friedman's Universe (5e) (page 436) regarding the Babcock model explanation
of the sun's magnetic field reversals.
-----begin quote----
There are also perplexing irregularities in the solar cycle. For example,
the overall reversal of the Sun's magnetic field is often piecemeal and
haphazard. One pole may reverse polarity long before the other. For
several weeks the Sun's surface may have two north magnetic poles and no
south magnetic poles.
-----end quote------
I guess I can understand how this can be, if there are two dipoles (with
the south poles in the interior) or some funky quadrupole configuration,
but my question is _why_ would this happen? What causes it? Would it be
because of different differential rotations in the north and south
hemispheres?
Thanks in advance,
Larry Smith
P.S. While we're at it, can anyone fill me in on the causes of the
reversals of the Earth's magnetic field as well? Page 210 of the same book
says Glatzmaier and Roberts did a computer simulation that (apparently
surprisingly) had field reversals like the real earth, but doesn't
elucidate on the cause.