Large scale magnetic dipole and multipole progressive waves in the photosphere

Abstract

The physical meaning of the photospheric short-period magnetic variation is interpreted. The motion of progressive waves along the equator with a 4.12 year circulation period may explain the basic feature of the variation. These waves have only one wavelength along the equator. The field distribution of one constituent of these waves is similar to that of a rotating dipole. The subharmonics of this dipole-wave are multipole terms circulating with periods of multiples of 4.12 years and the wave-lengths along the equator contain the same multiplying factor. The interference of the dipole and the multipole waves with a ‘background’ rotation and with the 27-day Bartels rotation time results in a series of periods recorded by the earlier published analysis. The relevant linear relationship for the angular velocities has also been proved based on the magnetic observation.