Fig. 9.From: Giant pulsations as modes of a transverse Alfvénic resonator on the plasmapauseSketch demonstrating the dependence of H (top) and (bottom) on lǁ and showing the probable locations of the transparent and opaque regions. Here ±l0 are the turning points for a harmonic with eigenfre-quency ω n , ±l I are the field-line intersection points with the ionosphere. The shaded areas, I and II, correspond to the transparent regions.Back to article page