Poleward moving auroral forms (PMAFs) are specific types of aurora believed to be the signature of the connection of Earth's magnetic field to that of the sun. In this paper, we discuss the evolution of PMAFs with regard to their auroral morphology as observed in all-sky camera images. We interpret different aspects of this evolution in terms of the connection dynamics between the magnetic fields of Earth and the sun. This sheds more light on the magnetic interaction between the sun and Earth.

This is the first survey of pulsating auroras which is differentiated by type. Pulsating auroras are found to be almost always an early-morning phenomenon and are almost entirely lacking persistent structuring before midnight. Long-lived patches which are known to move with convection primarily appear after midnight. These patches are a less common form of pulsating aurora and are found to originate from the inner magnetosphere, in agreement with past observations of their source region.

The wavelet transform was employed in nine HILDCAA events for intervals in which the Cluster crossed the magnetotail in order to identify the most energetic periods of these events in the magnetotail. It was seen that 76 % of the periods identified are ≤4 h. Using the cross wavelet analysis technique between B_z–IMF components and the B_x geomagnetic components, it was identified that the coupling of energy is stronger in periods between 2 and 4 h, which are typical substorm periods.

Flow channel extending in north–south directions is produced in the initial pulse of Pi2 pulsations associated with the field line dipolarization. Drifts in the ionosphere of the order of kilometers per second accumulated plasmas at the low-latitude end of the flow channel. The plasma compression in the ionosphere produced field-aligned currents, parallel electric fields, and auroral expansion. We called the compressive ionosphere a "dynamic ionosphere".