Figure 6From: Airglow-imaging observation of plasma bubble disappearance at geomagnetically conjugate pointsVirtual height of the ionosphere at 2 MHz obtained by an ionosonde at Yamagawa, Japan, on 8 August 2002. The horizontal arrow indicates the time interval (approximately 1600 to 1900 UT) during which the plasma bubble was observed in the airglow images.Back to article page