Why does the magnetic pole of the Earth flip?
The reason for the polarity reversal seems to be in the way that magnetic dynamos evolve in time. We see this process taking place in the sun every 22 years, so this makes it easier to study the process than for the earth’s field. According to the Parker Magnetic Dynamo Theory developed in the 1960’s, you need several ingredients including a conductive region that is spinning, and a convecting region. Lines of magnetic flux become wrapped around the rotating core and become buoyant. The float up into the convecting layer and become cyclonically twisted until they pop through the surface as ‘sunspots’. The sunspot fields are born with polarities such that the leading spot has the opposite polarity of the hemisphere it is in. If the large-scale field is dipolar, then the migration of these sunspot fields across the solar surface is supposed to neutralize some of the original dipolar field. As the sunspot cycle reaches its maximum, most of the spots are near the equatorial region and prod
