Measurements made on the S3-3 satellite within upgoing ion beams are used to determine what role the beam regions play in ionosphere-magnetosphere coupling and auroral particle acceleration. Numerical integrations over the measured electron and ion distributing functions provide estimates of the contributions of these energetic particles to bulk properties of the auroral plasma. It is found that energetic ions carry most of the parallel momentum flux and that energetic electrons carry most of the energy flux and field-aligned current within ion beam regions. We conclude that these energetic electrons carry upward field-aligned current all the way from the dense ionosphere to the distant magnetotail. The net current density carried by energetic electrons is associated with non-Maxwellian anisotropies (e.g., loss cones) in the electron distribution functions. These electrons are not well approximated by a drifting Maxwellian distribution. Microscopic stability analysis shows that the observed EHC waves can be driven by an ion beam. From the analysis, we find that there probably are very few cold electrons near the satellite when ion beams and EHC waves are detected. It also is suggested that the cold ion density may be maintained at a very low level within ion beams, although a larger density than that of the cold electrons. Cold electrons are likely to carry much of the downward field-aligned current adjacent to ion beams, where ion conics and higher frequency waves are observed. It is noted that some field-aligned current also could be transferred to cold electrons at the lower border of the acceleration region. Finally, momentum fluxes are used to investigate forces exerted by the acceleration process and the way these forces are transmitted from the ionosphere to the magnetosphere. The ion beam carriers a substantial momentum flux away from the acceleration region. This momentum flux must be provided from below by another particle species. If hot (10 eV to 100 eV) secondary electrons with a density of 10 to 100 cm-3 are trapped below the acceleration region, these electrons can supply the upward force needed to produce stable accleration. Otherwise, either the whole acceleration region of structures within it will be accelerated. More complete measurements at the lower edge of the acceleration region are required to distinguish between these possibilities.