A kinetic, multi-species model of the plasma-sphere is constructed that includes the effect of convection and corotation electric fields on trapped particles in drifting flux tubes. The resulting morphology of the outer plasmasphere is significantly different from the morphology obtained using the assumption of diffusive equilibrium. The difference is due primarily to the contraction and expansion of the region of velocity space accessible to the trapped particles, and has implications for the interpretation of remote sensing experiments.¿ 1997 American Geophysical Union