Optical (6300 ¿) observations of the polar cap region were recorded during the April to August austral winters of 1983 through 1986 with an image-intensified all-sky camera located at South Pole Station. Auroral structures seen in these all-sky images are correlated with the signatures registered by a meridian slit (keogram) imager. The keograms provide a covenient survey of auroral activity, but the all-sky images are required in order to determine the precise auroral morphology associated with the commonly observed keogram traces. Typical images of auroral activity around the diurnal period are presented. During morning and afternoon (magnetic local time) the auroal oval is usually seen crossing zenith, and frequent meridional movements appear on the keograms. During the midday interval, discrete poleward moving arcs occasionally appear, likely associated with flux transfer events or similar changes in the plasma flow pattern. Nightside keograms show the characteristic signatures of Sun-aligned arcs, which are well defined in the associated all-sky images. Two thirds of the Sun-aligned arcs are observed on the dawnside of local midnight. The arcs drift overhead at velocities of typically less than 250 m/s with reference to a Sun-oriented noncorotating frame. No significant preference is shown for easterly (dawnward) or westerly (duskward) dirft directions. These Sun-aligned arcs occur with greater frequency than previously thought: we observe a total of 114 such events during 219 diurnal periods of image collection. The available interplanetary magnetic field measurements, though limited, indicate Bz≥0 for two thirds of the Sun-aligned arcs. While no correlation is found between By and their local time distribution, there is a suggestion that dawnward motions appear preferentially with By>0 and duskward motions with By<0. ¿ American Geophysical Union 1989