This project will determine quantitative properties and causes of high-latitude F-region and topside ionospheric zone upflows. The PI will systematically examine the effects of at le4ast three candidate magnetospheric 'drivers' for such upflows: (1) effects of soft electron precipitation; (2) downward magnetospheric heat fluxes; and (3) convection-driven frictional ion heating. His methods used will be: (1) ionospheric fluid studies, (2) analysis of 200-800 km profiles of ionospheric plasma density, temperature and field aligned flow velocity measurements, and (3) analysis of DE-2 measurements of ionospheric and magnetospheric particles and fields. Preliminary investigations the PI has performed have produced two model-data comparison papers, which indicate in quantitative detail the importance of the soft electron precipitation effects as well as the magnetospheric electron heat fluxes. In addition, ion upfluxes significantly correlate with electron and temperatures, and ion field-aligned velocities have a direct relationship with the computed ambipolar electric field. Finally, substantial upflows occur only for soft electron precipitation average energies less than 100 eV. Further studies will be of widespread interest to CEDAR and the general ionospheric community.