Applied Mathematics Seminar

Dynamo theory has no difficulty in suggesting mechanisms for generating new magnetic flux for each cycle of solar activity. It does however encounter severe difficulties in removing the flux from the previous cycle to make way for the new.

Recent interest has focused on a model proposed by Ron Giovanelli shortly before his death in 1984. It was then considered to be heretical and was largely ignored. It postulated a poleward circulation at the solar surface which carries the new-cycle flux that erupts close to the equator to the poles. At the poles there has to be large-scale reconnection to allow some flux to be subducted by the deeper return flow and some to be carried off into the solar wind. This is now the fashionable picture with dynamo modellers.

It has the advantage or disadvantage, depending on point of view, of removing the problems to regions which are effectively out of sight. For solar observers, monitoring the poles presents a special challenge.

In this talk I will discuss some aspects of work in progress in conjunction with several institutions in the US that will, hopefully, provide some better illumination on the magnetic processes operating at the solar poles.