We use a self-consistent, semikinetic model to describe the steady state collisionless outflow of ions along diverging magnetic field lines at high altitude. The model is similar to that used by Barakat and Schunk (1983), but modified to (1) allow for anisotropic ion temperatures at the lower boundary, and (2) eliminate lower boundary potential jumps (''double layers''). The model is used to determine what happens to a typical, predominantly light-ion outflow when either the perpendicular or parallel (or both) ion temperatures are raised at the exobase lower boundary (4500 km altitude). Also, cases with plasma densities, bulk velocities, and temperatures characteristic of ion upwelling events (Moore et al., 1986) are shown. In addition, the escape flux of O+ ions for various combinations of electron and ion temperatures is investigated. It is shown that the O+ escape flux can be increased, to levels as high as obtained by Barakat and Schunk (1983) with electron temperatures of 104 K, by raising instead the ion temperatures, though to values considerably less than the ~105 K observed by Moore et al. (1986). ¿ American Geophysical Union 1988