Spatial Variations in Disturbance Ionospheric Currents Inference from 12
Geomagnetic Storms

The latitudinal and longitudinal variations of the disturbance ionospheric current including the effects of Prompt Penetration (PP) and Disturbance Dynamo (Ddyn) are investigated for during 12 geomagnetic storms 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 that

  • the effects of PP are abundant in main and recovery phases of the storms, frequently causing a reduction in EEJ amplitude. 

  • the trends of PP are largely invariant across longitudes for all phases of the storm. DI on EEJ reveal trends, which vary longitudinally with the phase of the storm. 

  • effects of Ddyn on the diurnal of low and equatorial stations show a seasonal pattern: westward increase in J and D seasons, while for E season moderate storms show eastward increase, larger ones show westward increase

  • at Equatorial latitudes DI influence varies longitudinally with phase of storm

Figure: Schematic representation of Ddyn current during (a) local noon and (b) local midnight, respectively.



Bulusu, J., Archana, R. K., & Arora, K. (2020). Spatial variations in disturbance ionospheric currents—Inference from 12 geomagnetic storms. Journal of Geophysical Research: Space Physics, 125, e2019JA027718. 10.1029/2019JA027718