Seasonal and intra-seasonal fluctuations of polar anticyclone and circumpolar vortex over Antarctica

Fluctuations of the polar anticyclone at sea level and the circumpolar vortex at 500mb are examined by using daily sea level and 500-mb weather maps of 1983. In addition to the seasonal cycle, a remarkable intra-seasonal fluctuation with the period of about 30 days is noticed in the intensity of polar anticyclone and in the circumpolar vortex. It is also noticed that in the seasonal time scale the intensity of polar anticyclone and circumpolar vortex shows a positive correlation while in the intra-seasonal time scale these two are negatively correlated.