Forcing of the Antarctic Circumpolar Wave by El Nino-Southern Oscillation teleconnections

Abstract

We address several issues regarding the Antarctic Circumpolar Wave (ACW). These include the extent to which the ACW is related to El Niño-Southern Oscillation (ENSO) cycles and the need to reconcile differences between the observed zonal wavenumber 2 pattern and the wavenumber 3 pattern found in coupled ocean-atmosphere models. In the present study we revisit the sea surface temperature (SST) signal of the observed ACW. We find that the associated SST variations may be decomposed into several empirical orthogonal functions (EOFs) that are linearly independent. The first four EOFs describe 84% of the total variance on timescales of 3-7 years, and superposition of SST signals of the four EOFs ..