A multi-decadal analysis was performed considering temperature anomalies at high latitudes of Southern South America (SSA) and Antarctic Peninsula. Temporal stability of the Pacific Decadal Oscillation (PDO) and the Southern Annular Mode (SAM) influence was considered for this purpose. Some researchers showed changes in the typical hemispheric circulation pattern associated with SAM between the 1960s–70s and 1980s–90s that impacted on Antarctic Peninsula's temperatures in spring. Significant negative correlations were found during the first decades and positive in the last decades. In this last case, the positive association was also observed with the southern stations of South America, and this result is congruent with a common variability behavior between SSA and Antarctic Peninsula temperature anomalies previously reflected in a cluster analysis. Running correlations considering the PDO index showed nonstationary impacts on temperature anomalies. These characteristics were analyzed with some reference station in a long period (over all the XX century).

It is known that climate series may exhibit jumps, periodic and quasiperiodic events that can be present for a sequence of years and then disappear or remain as weak signals in the system. A wavelet analysis was performed in order to analyze these aspects. A quasi-decadal variability was observed, with higher frequency signals since middle 90's.