An important part in ionosphere - magnetosphere coupling is the formation of upward ion flows from the ionosphere, as it provides a significant source of magnetospheric plasma .
Several mechanisms can lead to upward flow of ions.
Below altitudes of few hundred kilometers, frictional heating caused by strong perpendicular electric fields form isotropically heated ion distributions. This leads to an increased parallel pressure gradient, and ions flow upward to attain a new equilibrium scale height. The average ion temperature in the lower ionosphere is about 0.1 eV. Isotropically heated ions are only few times hotter, while perpendicular ion heating can produce energies in the hundreds of eV range. Ground-based radar measurements by Wahlund et al. It is possible that these outflow events are bulk plasma outflows with both electrons and ions moving upward.