Semi-annual, annual and Universal Time variations in the magnetosphere and in geomagnetic activity: 4. Polar Cap motions and origins of the Universal Time effect

Mike Lockwood, Carl Haines, Luke A. Barnard +4

We use the am, an, as and the a-sigma geomagnetic indices to the explore a previously overlooked factor in magnetospheric electrodynamics, namely the inductive effect of diurnal mo…