Progressing IMF B_Y-Related Polar Ionospheric Convection Disturbances
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A close correlation is frequently observed to exist between the dawn-dusk component of the interplanetary magnetic field (IMF <I>B<SUB>Y</SUB></I>) and the east-west component of the ionospheric convective flow and associated Hall currents (DPY currents) in the dayside polar cusp region. During intervals of southward interplanetary fields the IMF <I>B<SUB>Y</SUB></I>-related convection disturbances may progress from the cusp region, where they are first observed, across part of the dayside polar cap region. Examples of such progressing events as observed by an array of polar magnetometers, by an imaging riometer, and by an incoherent scatter radar are presented. The relations between the geomagnetic perturbations, the ionospheric absorption of radio waves, and the observed variations in the ion drift (convection) velocities, are discussed for the selected cases. These progressing disturbance events are considered to demonstrate the merging of the interplanetary field with the geomagnetic field extending from the polar regions in an open magnetosphere like the model first suggested by Dungey.
- Earth, Planets and Space
Earth, Planets and Space 47(8), 735-757, 1995-08
Society of Geomagnetism and Earth, Planetary and Space Sciences