Multi-stations Observations of the Atmospheric Electrical Parameters during Geomagnetic Disturbances

The effects of geomagnetic disturbances on the variation of atmospheric electric field over Maitri (70o 45' S, 11o44' E), Dome C (75° 06' S, 123° 20' E) and Vostok (78° 27' S, 106° 52' E) Antarctic research stations are presented in this work. For the first time the paper reports simultaneous observations of the atmospheric electric field from 2010 to 2012 of over three high latitude stations in Southern Hemisphere, and its associated changes due to geomagnetic disturbances. Near surface electric fields obtained from the three stations are analyzed. It is noted that the amplitude of change in surface electric field is highly dependent on the magnetic latitude during geomagnetic disturbances. The maximum deviation is observed near to the geomagnetic pole (Dome C) during strong magnetic perturbation, but not on the foci of the convection cells. It is due to the effective downward mapping of large scale horizontal ionospheric electric field. Interestingly, the phase of downward current is highly associated with magnetospheric electric field, moreover, its imprint is clearly observed in the magnetic and electric field variations on the earth's surface. The present observations provide an evidence for the changes on surface electric field due to spatial extension of convection cell. The inferences will be discussed in the conference.