Vertical profiles of noontime ionospheric plasma densities are shown in Fig. 4 for the case of R15. The left panel shows profiles in the region of maximum electron precipitation (78°) while the right panel shows densities at the sub-solar point (latitude 0°). Black lines denote the total electron density, blue lines are H+ and red lines H3+ densities. Not shown individually are profiles of other ions calculated in the model, namely H2+, CH3+, CH4+, CH5+, H2O+ and H3O+. The hydrocarbon densities populate the bottomside ionosphere, accounting for most of the electron density below around 1000 km altitude.
region of maximum electron precipitation
78°
°
sub-solar point
latitude
0°
°
altitude
below around 1000 km
km