Combined measurements of EISCAT and the EISCAT magnetometer cross to study Ω bands

A combination of incoherent scatter radar data and data from a magnetometer array complement each other in an ideal way. The magnetometer results help to distinguish between temporal and spatial fluctuations in the radar data, and the radar results provide a means to separate magnetometer‐inferred equivalent currents into their Hall and Pedersen components. The technique is used to study Ω bands and leads to a better understanding of the ionospheric current structure associated with this phenomenon. In extending previous models we propose a pair of counterrotating source free ionospheric current vortices driven by field‐aligned currents, an upward current centered in the luminous part of the Ω band and a downward current in the dark part with its center about 400 km west of the upward current.