Formation of solar prominences by flux convergence

Observations have found three main conditions that have to be fulfilled bef ore a prominence will form. These are the presence of a magnetic arcade, a transport of flux toward the polarity inversion line under the arcade, and cancellation of magnetic flux that approaches the polarity inversion. We ha ve set up a three-dimensional model that initially contains two bipolar reg ions, representing new and old regions of flux on the Sun. The regions are forced together by an imposed velocity flow on the lower boundary. As they approach one another, the magnetic field reaches a state where a thin curre nt distribution is created above the polarity inversion line. When the curr ent becomes strong enough, magnetic reconnection starts. In the right param eter regime it is found that the reconnected field lines are able to lift p lasma several pressure scale heights against gravity. The lifted plasma for ms a region with enhanced density above the current sheet, along the polari ty inversion line and with a length that is longer than the length of the c urrent sheet. Different types of field line connectivity are found that pro vide the force to lift mass as the reconnection proceeds.