Electrical and electrothermal conductivity of planetary ionospheres, 1: Refinement of theory

The explicit form of the coefficients of the electrical and electrothermal conductivity of electrons in a magnetic field in a multicomponent ionosphere with allowance for the temperature difference between electrons and heavy constituents is determined in the first, second, and third approximations of the Sonin polynomial expansion of the Chapman-Enskog method. General expressions for the electron transport coefficients are obtained, which are reduced to a form convenient for practical application. In the first approximation, equations are derived for determining the ion diffusion velocities in a magnetic field in a multicomponent gas mixture. Approximating expressions are refined for the collision frequencies of electrons with the principal neutral constituents of the upper planetary atmospheres. Equations for determining the ambipolar-diffusion velocities of ions in a multicomponent ionosphere in the absence of a magnetic field (or parallel to it) are obtained in the first, second, and third approximations.