Transport properties of the partially ionized ionosphere

The level of ionization and transport properties in the Earth's E and F layers are interrelated and vary due to electron-neutral, ion-neutral, ion-ion, and ion-electron collisions at various altitudes. Mobility of the ions, or the ion-Hall parameter β_i (given by the ratio of the ion-cyclotron to the collision frequency), determines the relative importance of the various (i.e., Ohm, Hall, and Pedersen) conductivities, parallel, perpendicular, and cross (with respect to the magnetic field) viscosities, and thermal conductivities. Whereas perpendicular viscosity and thermal conductivity due to ions are 1 / β_i² smaller than the parallel ion viscosity, both the parallel and perpendicular viscosities and thermal conductivities due to neutrals are of the same order. Further, the perpendicular component of the viscosity and thermal conductivity are a weak function of ion-Hall parameter. Using the E and F layers' ionospheric data, we calculate various transport coefficients and show that the perpendicular transport coefficients are of the same order as the parallel transport coefficients. For completeness, we also give an expression for the Ohm, Hall, and Pedersen diffusivities, which could be important in the lower layer of the ionosphere.