| Session Details | |
| Section | ST - Solar & Terrestrial Sciences |
| Session Title | Stormtime Penetration Electric Fields and Disturbance Dynamo: Magnetospheric and Ionospheric Perspectives |
| Main Convener | Prof. Takashi Kikuchi (Nagoya University, Japan) |
| Co-convener(s) | Dr. Bhaskara Veenadhari (Indian Institute of Geomagnetism, India) Prof. Chien-Ming Huang (National Central University, Taiwan) |
| Session Description | Magnetic storms represent the largest disturbances in magnetosphere and ionosphere. During the main phase of magnetic storms, the interplanetary magnetic field (IMF) is generally southward and associated with increased rate of reconnection at dayside of magnetopause, thus driving an enhanced overall convection in the magnetosphere. The enhanced magnetospheric convection electric field, in turn, penetrates into the inner magnetosphere and low latitude ionosphere and increases the equatorial DP2 currents. Shielding/overshielding electric field, on the other hand, tends to prevent the penetration or even reverse the electric field at low latitude. The disturbance dynamo (DD) which also alters the ionospheric electric fields is believed to be driven mostly by electrodynamic action of storm-time enhanced winds. The ionospheric electric fields have a potential to noticeably affect the ionospheric transport and chemistry of electron density layers, thus have effects on the equatorial ionization anomaly (EIA). Prompt penetration electric fields (PPEFs) play a critical role in storm-time magnetosphere-ionosphere coupling and has reached substantial understanding, but critical problems or controversies remained unsolved. How long can the interplanetary/magnetospheric electric field penetrate into low latitude ionosphere? What determines the duration and strength of penetration electric fields? The time scales of the DDEF and PPEF are important in assessing their effects on the global ionosphere. These questions can be addressed with the analysis of available ground ionosonde and magnetometer data from equatorial to high latitudes, incoherent scatter radar measurements of ionospheric electric fields and satellite data and can be compared to existing models. Contributions addressing these issues are invited to this special session. The topics for this special session include penetration of electric fields, storm-time equatorial electrojet variations, disturbance dynamo mechanisms, and perturbations in ionospheric electric field during magnetic storm periods. Particularly welcome are papers on all aspects (observations, data analysis methods, simulations and theoretical studies) and highlighting the coupling processes between the different domains in this complex system. |