It is the first time that a rare aurora of this kind has been seen from the ground, and it came at a time when the gusts of the, move and pulsate, with clearly discernible shapes in the sky. These auroral displays are powered by electrons from the solar wind — a stream of charged particles that flow from the sun — that become trapped in an extension of — a large ejection of plasma and magnetic field from the sun— is released, the magnetotail can be pinched off .
At the location of coronal holes, the sun's magnetic field lines are open — they don't loop back onto the sun's surface, the photosphere. As the open magnetic field lines extend out into space the coronal hole forms the base of a magnetic funnel out of which stream high-energy electrons. Normally we don't notice this happening, because the regular polar wind particles scatter the fast-wind electrons emanating from the coronal hole. On this occasion, however, the pressure of the solar wind had decreased to the extent it was negligible, and the fast-wind electrons could reach Earth unhindered.
The clinching evidence was that the DMSP satellites only saw the polar rain aurora over Earth's north magnetic pole, which is tilted towards the sun during Northern Hemisphere winter.