[en] A time-dependent, three-dimensional, multi-ion numerical model of the global ionosphere was used to study the asymmetry in large-scale ionospheric features between the northern and southern hemispheres. The comparisons were done for June and December solstice conditions at solar maximum for quiet geomagnetic activity. In comparing the ionospheric densities in the northern and southern hemispheres for a given season, the authors found the following: (1) the winter hemispheres display the most marked universal time (UT) variations due to the displacement between the geomagnetic and geographic poles, (2) the summer high-latitude and equatorial densities in both hemispheres are morphologically similar. (3) In the winter hemispheres, the corresponding electron densities are again morphologically similar but can be very different quantitatively due to the different dipole offsets, (4) for a given season, the density difference between the northern and southern hemispheres displays a marked UT dependence, (5) the winter mid-latitude trough is the feature that exhibits the largest northern-southern hemisphere difference due to the different dipole tilts, and (6) the winter anomaly is present in the northern hemisphere at almost all UTs, while it is essentially absent in the southern hemisphere