Global-scale modes of surface temperature variability on interannual to century timescales

Abstract

Using 100yr of global temperature anomaly data, we have performed a singular value decomposition of temperature variations in narrow frequency bands to isolate coherent spatio-temporal "modes' of global climate variability. Secular variance is dominated by a global coherent trend, with nearly all grid points warming in phase at varying amplitude. A smaller, but significant, share of the secular variance corresponds to a pattern dominated by warming and subsequent cooling in the high latitude North Atlantic with a roughly centennial timescale. Spatial patterns associated with significatn peaks in variance within a broad period range from 2.8 to 5.7yr exhibit characteristic El Nino-Southern Oscillation (ENSO) patterns. A recent transition to a regime of high ENSO frequency is suggested by our analysis. -from Authors