WEIGHTED CURRENT SHEETS SUPPORTED IN NORMAL AND INVERSE CONFIGURATIONS - A MODEL FOR PROMINENCE OBSERVATIONS

We analyze the magnetic support of solar prominences in two dimensions by using a technique which incorporates both photospheric and prominence magnetic field observations. The prominence is modeled by a mass-loaded current sheet which is supported against gravity by magnetic fields from a bipolar source in the photosphere and a massless line current in the corona. With this system, we find that prominence support can be achieved in three different kinds of configurations: (a) an arcade topology with a normal polarity, (b) a helical topology with a normal polarity, and (c) a helical topology with an inverse polarity. In all cases the important parameter is the variation of the horizontal component of the prominence field with height. In the arcade topology, only configurations where the field decreases with height can be supported, but in the helical topology, configurations can be supported even when the field does not decrease with height. For a helical topology with normal polarity the horizontal field component must remain nearly constant with height, but for a helical topology with inverse polarity the horizontal field component can increase with height provided that the increase does not exceed a critical value. Adding a line current external to the prominence eliminates the nonsupport problem which plagues virtually all previous prominence models with inverse polarity.