Electron density from RPC-MIP n_e plotted in high-resolution (gray dots) and smoothed over 60 points (black dots) on 19 February 2016. The modeled ionospheric densities derived assuming photoionization alone and both photoionization and electron-impact ionization are shown in blue and red, respectively. The colored shaded areas represent the range of ion bulk velocities considered from 900 m s^-1 (lower boundary in n_i) to 570 m s^-1 (upper boundary in n_i).