Fig. 4From: Dependence of the high-latitude plasma irregularities on the auroral activity indices: a case study of 17 March 2015 geomagnetic stormExamples of the digital ionograms recorded at 1730–1745 UT during 16 March (top) and 17 March (bottom) by Boulder, Juliusruh, and Mohe digisonde stationsBack to article page