Open AccessSolar wind density controlling penetration electric field at the equatorial ionosphere during a saturation of cross polar cap potential
Author(s) -
Wei Y.,
Wan W.,
Zhao B.,
Hong M.,
Ridley A.,
Ren Z.,
Fraenz M.,
Dubinin E.,
He M.
Publication year - 2012
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2012ja017597
Subject(s) - ionosphere , electric field , interplanetary magnetic field , geophysics , solar wind , interplanetary spaceflight , physics , ionospheric dynamo region , atmospheric sciences , ring current , computational physics , polar , magnetosphere , magnetic field , astronomy , quantum mechanics
The most important source of electrodynamic disturbances in the equatorial ionosphere during the main phase of a storm is the prompt penetration electric field (PPEF) originating from the high‐latitude region. It has been known that such an electric field is correlated with the magnetospheric convection or interplanetary electric field. Here we show a unique case, in which the electric field disturbance in the equatorial ionosphere cannot be interpreted by this concept. During the superstorm on Nov. 20–21, 2003, the cross polar cap potential (CPCP) saturated at least for 8.2 h. The CPCP reconstructed by Assimilative Mapping of Ionospheric Electrodynamics (AMIE) procedure suggested that the PPEF at the equatorial ionosphere still correlated with the saturated CPCP, but the CPCP was controlled by the solar wind density instead of the interplanetary electric field. However, the predicted CPCPs by Hill‐Siscoe‐Ober (HSO) model and Boyle‐Ridley (BR) model were not fully consistent with the AMIE result and PPEF. The PPEF also decoupled from the convection electric field in the magnetotail. Due to the decoupling, the electric field in the ring current was not able to comply with the variations of PPEF, and this resulted in a long‐duration electric field penetration without shielding.