The classical and anomalous transport properties of a multifluid plasma consisting of H+, O+, and electron populations in the presence of auroral field-aligned return currents are investigated, using a multimoment fluid model with anomalous transport coefficients. This approach offers the possibility of simulating large-scale dynamic phenomena without neglecting the important macroscopic consequences of microscopic processes such as anomalous resistivity and turbulent heating. The macroscopic effects of the electrostatic ion cyclotron (EIC) instability (perpendicular ion heating) and of an EIC-related anomalous resistivity mechanism which heats the electrons are included in the present version of the model. The responses of the outflowing polar wind plasma to the application of current, with and without instabilities, are exhibited. The simulations show that the electron drift velocity corresponding to a return current of 0.65 &mgr;A/m2 is above the threshold for EIC waves. Downward electron heat flow competes with upward convection and adiabatic effect to determine the direction of the electron temperature anisotropy. Resistive electron heating lowers the critical drift velocity for marginal EIC stability and leads to enhanced ion heating. The model predictions are compared with the experimental observations where possible. ¿ American Geophysical Union 1987