Abstract:

A methed of multi-spectral analysis is used to study the spectral characteristics of surface and upperlevel meteorological elements over the Great Wall Station (62°12' S, 58°57' W) on Antarctica and their phasecorrelation, propagation of mean oscillation at 500hPa level in the Southern Hemisphere and their corresponding synoptic sense. the results are summed up as follows: 1.Over the sub-Antatctic zone, as in the Northern Hemisphere there generally exist quasi- weekly oscillation and quasi-biweekly oscillation. In different seasons the oscillations of meteorological elements are different: in winter season quasi-biweekly oscillation is dominant, while in summer season quasi-weekly oscillation is dominant. 2.From the Earth's surface to the lower stratosphere there is a distinct quasi-weekly oscillation at each isobaric surface, but the most intense oscillation appears at 200-300hPa, and the oscillations of height and temperature are propagated downward. 3.Both in winter and summer seasons the quasi-biweekly oscillation are propagated from west to east, and the mean velocity of its propagation is about 7-17 longtitude / day. 4.The quasi-biweekly oscillation and the quasi-weekly oscillation over the sub-Antarctic zone are closely related to the activity and intensity variation of polar vortex at 500hPa, while at 1000hPa they refleet an interaction between the circumpolar depression and the sub-tropical high over Antatctica. The quasi-biweekly oscillation may be a reflection of inherent oscillation of the polar vortex, where as the quasi-weekly oscillation is a reault of forced oscillation by external disturbance. A large number of calculations and analysis made reveals the features of medium-range oscillation over the sub-Antarctic zone. The results are of significance for understanding the behaviour of synoptic dynamics and making the weather forecast. This work is supported by National Committee for Antarctic Research.