  To better understand diffuse ionized gas kinematics and halo rotation in
spiral galaxies, we have developed a model in which clouds are ejected from the
disk and follow ballistic trajectories through the halo. The behavior of clouds
in this model has been investigated thoroughly through a parameter space search
and a study of individual cloud orbits. Synthetic velocity profiles have been
generated in z (height above the plane) from the models for the purpose of
comparing with velocity centroid data from previously obtained long-slit
spectra of the edge-on spirals NGC 891 (one slit) and NGC 5775 (two slits). In
each case, a purely ballistic model is insufficient in explaining observed DIG
kinematics. In the case of NGC 891, the observed vertical velocity gradient is
not as steep as predicted by the model, possibly suggesting a source of
coupling between disk and halo rotation or an outwardly directed pressure
gradient. The ballistic model more successfully explains DIG kinematics
observed in NGC 5775; however, it cannot explain the observed trend of high-z
gas velocities nearly reaching the systemic velocity. Such behavior can be
attributed to either an inwardly directed pressure gradient or a possible tidal
interaction with its companion, NGC 5774. In addition, the ballistic model
predicts that clouds move radially outward as they cycle through the halo. The
mass and energy fluxes estimated from the model suggest this radially outward
gas migration leads to a redistribution of material that may significantly
affect the evolution of the ISM.
