Activated solar filaments and flares

Skylab observations have shown that activations and disruptions of dark H-alpha filaments are one of the basic and most important mechanisms of solar activity. The Kopp-Pneuman theory of post-flare loops shows that the process which disrupts a filament opens the magnetic field and causes a greatly enhanced mass flow along the field lines. The open field lines subsequently reconnect, starting from the bottom of the corona and proceeding upwards. This process can last for many hours. Hot loops are first seen in X-rays, then in extreme UV lines, and, after an appropriate cooling time, in H-alpha as the loop prominence systems.