A DYNAMICAL MODEL OF MAGNETIC CLOUDS

Magnetic clouds observed in interplanetary space are probably the inte rplanetary manifestations of coronal mass ejections. A looplike magnet ic cloud is modeled as a gigantic flux rope that moves through the mag netized medium of the solar wind. The dynamics of a model cylindrical magnetic cloud is used to elucidate the motion of magnetic clouds and their expansion in interplanetary space. Previous models of magnetic c louds with the assumption of either force-free magnetic field or magne tohydrostatic equilibrium preclude the consideration of motion. The dy namical model, based on flux rope dynamics, allows the inclusion of fo rces that drive the motion of the magnetic clouds relative to the sola r wind.