Plasma drift in the solar corona

Abstract

Model calculations of plasma drifts in the solar corona were performed. We established that only drifts in crossed fields could result in velocities V of several hundred kilometers per second. Such velocities are typical of coronal mass ejections (CMEs). We derived an analytic expression for V where n, the expansion harmonic of the magnetic-field strength, varies with time. As follows from this expression, V is a power function of the distance with index (2−n) and the radial component changes sign (n−1) times in the latitude range from −π/2 to +π/2. We found that if the magnetic dipole moment varies with time, the similarity between the spiral structures of coronal plasma is preserved when they displace within several solar radii and the density gradient at the conical boundaries increases (the apparent contrast is enhanced). There is a correspondence between the inferred model effects and the actually observed phenomena that accompany CMEs.