Analysis on 10 hPa Polar Vortex Multi-Scale Variable Characteristic in the Southern Hemisphere

Using the 1948—2007 NCEP/NCAR reanalysis monthly geopotential dataset,a set of circulation indices are defined to characterize the polar vortex at 10 hPa geopotential height of the Southern Hemisphere,including area-(S),intensity-(P) and centre position-(λ_c,(?)_c) indices.The results show that.(1) there is anticyclonic(cyclonic) from December to January(form March to October) around high latitude at 10 hPa.The circulation patterns change in February and November(2) The interannual anomalies of anticyclonic and cyclonic both change notably in the later 1970's.Before that,the anticyclonic(cyclonic) strengthens(weakens) from weaker(stronger) to climatological normals.After the later 1970' s, the anticyclonic tends to climatological normals gradually,as the cyclonic oscillates in the weak state.(3) Their centre positions also have corresponding change.There are obvious interannual(interdeeadal) variations of anticyclonic(cyclonic).(4) The ozone anomaly can cause interannual variations of anticyclonic anomaly in January.(5) There is so notable negative correlation between the index of P and AAOI that P can represent AAOI.