Prompt Penetration Equatorial Electric Field Model 

Real-time Electric field 


Transfer function model 

Climatological Model 

Data & processing 




Wind driven currents in the ionosphere coupled with the Earth's magnetic field produce the Equatorial Electric Field (EEF), which is responsible for driving many interesting ionospheric phenomena. The EEF is known to be highly variable from day to day, primarily as a result of solar wind electric fields penetrating from high latitudes to the equator, in addition to variabilities in the neutral winds coming from below. This work realistically models the time variations coming from the solar wind, which are mapped from interplanetary electric field (IEF) data through a transfer function model. The transfer function was derived from 8 years of IEF data from the ACE satellite, radar data from JULIA, and magnetometer data from the CHAMP satellite. This model also provides the climatology of the EEF, which is based on six years of magnetometer measurements from the CHAMP satellite. The model accepts as input a time and location and produces the best estimate of the EEF for those parameters.

Fig 1

Fig. 1: (Left) Input to the prompt penetration (PP) part of the model. (Right) Output from the PP model



Manoj, C., S. Maus, and P. Alken (2013), Long-period prompt-penetration electric fields derived from CHAMP satellite magnetic measurements, J. Geophys. Res. Space Physics, 118, 5919–5930, doi:10.1002/jgra.50511. 

Manoj, C., and S. Maus (2012), A real-time forecast service for the ionospheric equatorial zonal electric field, Space Weather, 10, S09002, doi:10.1029/2012SW000825. 

Manoj, C., S. Maus, H. Lühr, and P. Alken (2008), Penetration characteristics of the interplanetary electric field to the daytime equatorial ionosphere, J. Geophys. Res., 113, A12310, doi:10.1029/2008JA013381.