The conductosphere depth at equatorial latitudes as determined from geomagnetic daily variations

The structure of the conductosphere at equatorial latitudes is investigated by analyzing geomagnetic daily variations (GDV) data. To do so the magnetic field induced in a multilayered model by an external source of finite size that reproduces the external part of these variations is computed; latitudinal profiles of the total field produced at ground by the assumed external source are then found and compared with the measured GDV data. Results are applied to equatorial zones in Peru, Africa and India.