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Abstract

The conjugacy effects of the ionospheric scintillation obtained from GPS measurements during the geomagnetic storms of October 2003, November 2003 and July 2004 have been investigated at the approximately geomagnetically conjugate points over the polar regions: Scott Base station; Antarctica (SBA) (GC: 77.85°S, 166.76°E; CGM:-79.94°S, 327.23°E) and Resolute Cornwallis Island station (RESO) at the high Arctic region (GC: 74.69°N`, 265.12°E`; CGM: 83.17°N`, 320.95°E`). The measurements aims at investigation of the similarities and differences of the storm time ionospheric scintillation activities occurring at the conjugate points and study its relationship with the Storm Enhanced Density (SED) over the polar regions. The statistical measurements during these storm events over both hemispheres showed asymmetrical occurrences of the ionospheric scintillation at the conjugate points. During these magnetic storms, pronounced scintillation activity was observed at the nightside hemisphere with the total daily scintillation were higher by a factor of 1.1, 4.2 and 32, respectively and the periods of the ionospheric scintillation are longer by a factor of 1.6, 2.5 and 3.8, respectively. The measurements showed that the periods of intense scintillation at both stations were corresponding to the presence of the SED events which were more pronounced over the nighttime hemisphere. The SED magnitudes over the nightside hamisphere were higher by a factor 1.5-2.1 during the October 2003 storm, factor of 2 during the November 2003 and factor of 5 during July 2004 storm.