A conductivity model for the Brazilian equatorial E-region: Initial results

Abstract

This paper presents results from a new model of field-line-integrated ionospheric conductivity for the Brazilian equatorial region. It was developed aiming to calculate zonal electric fields at E-region heights In the equatorial region. The present model is based on a constant neutral atmosphere model and on an empirical electron densities model (which also gives the ion composition) adjusted by E-region electron density measured by digisonde. It is also based on a geomagnetic field model that we approximate with a dipole which is not located at the centre of the Earth due to the large magnetic declination angle In the Brazilian sector. We have also considered the eccentric dipole having an inclination of 20° with respect to the Earth rotation axis. The conductivities are calculated for the year 2002 and the results from the present model are compared to those obtained from the conductivity model of the Kyoto University. © 2007 Sociedade Brasileira de Geofísica.