Meridional equatorial electrojet current in the American sector

Huancayo is the only equatorial electrojet station where the daytime increa se of horizontal geomagnetic field (H) is associated with a simultaneous in crease of eastward geomagnetic field (Y). It is shown that during the count er electrojet period when Delta H is negative, Delta Y also becomes negativ e. Thus, the diurnal variation of Delta Y at equatorial latitudes is sugges ted to be a constituent part of the equatorial electrojet current system. S olar flares are known to increase the H field at an equatorial station duri ng normal electrojet conditions (nej). At Huancayo, situated north of the m agnetic equator, the solar flare effect, during nej, consists of positive i mpulses in H and Y and negative impulse in Z field. During counter electroj et periods (cej), a solar flare produces a negative impulse in H and Y and a positive impulse in Z at Huancayo. It is concluded that both the zonal an d meridional components of the equatorial electrojet in American longitudes , as in Indian longitudes, flows in the same, E region of the ionosphere.