Connection of the Interannual Variations of the Arctic and Antarctic Oscillations with Eddy and Wave Activity Characteristics

摘要

One of the problems in an investigation of the Arctic and Antarctic oscillations is the lack of a clear definition of a mechanism driving the oscillations. The primary cause is most often considered to be a positive feedback between zonal velocity and transfer of angular momentum by eddy and/or wave disturbances. Comparison of the variations of the oscillation indices and characteristics of eddy (wave) activity gives no strong evidence of this hypothesis. The anomalies of the calculated correlation curves are less significant and less regular than those of the correlations between oscillation indices and average zonal characteristics of the meteorological fields. The difference in the spatial structure of wave activity and zonal velocity anomalies is most pronounced in the Southern Hemisphere. Probably, most of the wave and eddy disturbances linked to the oscillations are not the cause but the effect of these oscillations, for example, in the interaction of varying zonal flows with mountain masses.