Low‐frequency variability of the Antarctic Circumpolar Wave

This study evaluates the Antarctic Circumpolar Wave (ACW) variability in the Southern Ocean using a 27‐year series of sea surface temperature (SST) and sea level pressure (SLP). From a cross‐covariance analysis we find that the strongest covariation between the extratropical wavenumber‐2 in SST and in SLP is during the austral summer in the South Pacific Ocean. Examination of the time series reveals two timescales of variability. A wavenumber‐2 structure in SST and SLP anomalies correlates well at interannual (IA) timescales, when ENSO‐driven teleconnections seem to energize the ACW. Moreover, in the 1973‐1999 epoch, the ACW has been modulated by interdecadal (ID) variability possibly related to the Southern Oscillation.