Characteristics of the Antarctic Circumpolar Wave during Recent 100 Years

The phenomenon known as the Antarctic Circumpolar Wave (ACW) was determined to have occurred during the last two decades of the 21th century. In this study, a new reanalysis dataset of 20th century reanalysis Version 2 (20CRV2) spanning 1871-2008 and several long-term observation series were used to investigate the interdecadal fluctuation and transmission of the ACW since 1871. The results indicate an obvious interdecadal variation of the ACW signal, which occurred in 1940-1960 and in 1980-2000 and disappeared during the other periods. The greatest amplitude of the ACW was detected near the southeast Pacific, implying the essential influence of ocean-atmosphere interaction at this region to the emergence of the ACW. Moreover, it was determined that a noticeable ACW phenomenon appeared during the period in which the Antarctic Oscillation (AO) was relatively stronger, which indicates that the enhanced AO may intensify the circumpolar westerly and benefit the emergence of the ACW.