On the origin and maintenance of the Sun's electric field

Abstract

The systematic motion of the Sun's conducting atmosphere across its own magnetic field is shown to modify greatly the effective electrical conductivity of the region. The velocity of the superposed mass‐motion of the atmosphere due to the impressed crossed electric and magnetic fields is found to be E/B to a very good approximation. It is shown that the processes of ionization and recombination of ions and electrons subject simultaneously to impressed electric and magnetic fields result in a systematic migration of the ions. The greater probability of electrons recombining when they possess a minimum of energy results in a transport of charge in a direction opposite to the motion imposed by electrical conduction. The magnitude of this systematic motion in the Sun is adequate to replenish the Sun's electric charge and hence maintain a steady electric field.Electrical equilibrium in the reversing layer is determined by “three‐body” recombinations and the electronic conductivity, whereas equilibrium in the chromosphere is determined by “two‐body” recombinations and the ionic conductivity. The latter equilibrium is of such a type that high effective electron‐temperatures must exist in the chromosphere and this is adequate to explain both the presence of certain solar bright‐line spectra such as the ionized helium line λ 4868 and the observed chromospheric pressure‐gradients. The estimated effective temperature of the chromospheric ions approximates 26,000°.The superposed atmospheric velocity and electric fields calculated from the present theoretical considerations agree in magnitude, direction, and distribution with those deduced in earlier papers from observational data regarding the anomalous solar rotation [Phys. Rev., 35, 635–642 (1930), and 36, 1251–1256 (1930)].