Spatial Variations in Disturbance Ionospheric Currents—Inference From 12 Geomagnetic Storms

• Published in: Journal of geophysical research. Space physics 2020-08, Vol.125 (8), p.n/a
• Main Authors: Bulusu, Jayashree, Archana, R. K., Arora, Kusumita
• Format: Article
• Language: English
• Subjects: disturbance dynamo; disturbance ionospheric currents; Geomagnetic stations; geomagnetic storm; Geomagnetic storms; Geomagnetism; Hemispheres; Ionospheric currents; Magnetic storms; prompt penetration; Seasonal variations; Storms
• ISSN: 2169-9380; 2169-9402
• DOI: 10.1029/2019JA027718

In this paper, we investigate the latitudinal and longitudinal variations of the disturbance ionospheric current during 12 geomagnetic storms with Dst ranging between −50 and −130 nT. For this purpose, data from 15 geomagnetic stations along three longitudinal sectors at 70°E, 77°E, and 93°E, ranging from middle to equatorial latitudes in both hemispheres are analyzed. Our study reveals the pattern of PP in the different phases of the storm and the competing effects of PP and Ddyn during the recovery phase of the storms. The PP signatures are mainly comparable across longitudes, irrespective of the strength and phase of the storm. The effect of Ddyn shows a seasonal pattern, which is influenced by the strength of the storm. The location of the antifoci during each storm shows latitudinal variability. Key Points DI signatures including PP and Ddyn are investigated over 20° longitudes from north middle to south midlatitudes PP events are observed in all phases of the storms; longitudinal trends vary with each storm The effect of Ddyn shows a seasonal pattern with varying foci of anti‐Sq, which is influenced by the strength of the storm