Subauroral electric fields and magnetospheric convection during the April, 2002 geomagnetic storms

• Published in: Geophysical research letters Vol. 31; no. 11; pp. L11801 - n/a
• Main Author: Anderson, P. C.
• Format: Journal Article
• Language: English
• Published: American Geophysical Union 01-06-2004; Blackwell Publishing Ltd
• Subjects: Electric fields; Magnetosphere/ionosphere interactions; Magnetosphere—inner; Magnetospheric Physics; Storms and substorms
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2004GL019588

We analyze the ionospheric electric fields during the geomagnetic storms of April, 2002 using data from the DMSP satellites. The subauroral potential drop (ΦSA) in the evening sector exceeded 60 kV at times and was often a substantial fraction of total cross‐polar‐cap potential drop (ΦPC). At storm commencement, the subauroral electric field penetration moved rapidly equatorward reaching the lowest magnetic latitude well before the end of the storms' main phases. ΦPC and ΦSA were correlated well with AE with no time delay. However, the correlations of ΦPC and ΦSA with Dst occurred with significant time delays, about an hour for ΦPC and longer for ΦSA. The largest values of ΦPC were seen near the end of the storm main phases while the largest values of ΦSA were seen well into the recovery phases. The results of this study have important implications on models attempting to describe the dynamics of the plasmasphere, the inner magnetosphere and the ring current.