Moreover, the complexities of F2 layer behaviour can be understood in terms of: (1) chemical changes, because the electron density equilibrium depends strongly on the [O]/[N2] ratio and also on the [O]/[O2] ratio; (2) diurnal heating and cooling, since the height distribution of the F2 layer is governed by the plasma scale height, Hp = K (Ti + Te) /mi g (see Eq. 2.3.6); (3) winds in neutral air at heights around 300 km that range between tens and hundreds of ms−1, at midlatitudes directed towards the poles by day and towards the equator at night; and
(4) electric fields, since the electrical structure and dynamics of the upper atmosphere generate electrodynamic drifts in the F region that can significantly modify the vertical distribution of ionization. However, because of the dip angle of the magnetic field, the effects of electric fields are much more important for the equatorial ionosphere while the effects of neutral winds are much more important at mid-latitudes.