MAGNETICALLY DRIVEN WIND FROM AN ACCRETION DISK WITH LOW-INCLINATION FIELD LINES

The inclination of the field lines at the surface of an accretion disk has a strong influence on the nature of the resulting magnetically dr iven wind. If the field lines are steep, a hot corona must be present to feed the wind, at low inclinations the wind is fed directly from th e surface. With a simple model for the field distribution in a disk we show how the transition between the two regimes takes place. At high inclinations an ordinary wind of the stellar type results. At low incl inations, a high- m wind results with very low terminal speed and high ly wound-up field lines. We argue that the latter type of wind will be highly unstable to nonaxisymmetric (Parker type) instabilities, and t hat it gives rise to a magnetically driven circulation along the disk surface rather than a high density wind.