E region electric field dependence of the solar activity

Abstract

We have being studying the zonal and vertical E region electric field components inferred from the Doppler shifts of type 2 echoes (gradient drift irregularities) detected with the 50MHz backscatter coherent radar set at SAo Luis, Brazil (SLZ, 2.3 degrees S, 44.2 degrees W) during the solar cycle 24. In this report we present the dependence of the vertical and zonal components of this electric field with the solar activity, based on the solar flux F-10.7. For this study we consider the geomagnetically quiet days only (Kp3(+)). A magnetic field-aligned-integrated conductivity model was developed for proving the conductivities, using the IRI-2007, the MISIS-2000, and the IGRF-11 models as input parameters for ionosphere, neutral atmosphere, and Earth magnetic field, respectively. The ion-neutron collision frequencies of all the species are combined through the momentum transfer collision frequency equation. The mean zonal component of the electric field, which normally ranged from 0.19 to 0.35mV/m between the 8 and 18h (LT) in the Brazilian sector, show a small dependency with the solar activity. Whereas the mean vertical component of the electric field, which normally ranges from 4.65 to 10.12mV/m, highlights the more pronounced dependency of the solar flux.