Based upon coupled climate simulations driven by present day and glacial boundary conditions, we demonstrate that the internal variability associated with the pronounced south polar climate anomalies that characterized the glacial climate regime was largely confined to the winter season. In particular, the intensity and spatial structure of the Antarctic Oscillation/Southern Annular Mode is found to display a strong seasonal cycle. In the summer season, we demonstrate that this mode of internal climate variability is extremely robust in response to a change from modern to glacial conditions in that it seems not to depend upon the latitudinal position of the baroclinic zone nor on the strength of the mean atmospheric zonal circulation. In winter, however, and under glacial conditions, this mode is characterized by a significantly modified atmospheric circulation that differs dramatically in terms of its internal variability from that characteristic of modern conditions