Spatial correlations of interdecadal variation in global surface temperatures

We have analyzed spatial correlation patterns of interdecadal global surface temperature variability from an empirical perspective. Using multi‐taper coherence estimates from 140‐yr records, we find that correlations between hemispheres are significant at ≳95% confidence for non‐randomness for most of the frequency band 0.06 <f <0.24 cyc/yr. Coherence estimates of pairs of 100‐yr grid‐point temperature data series near 5‐yr period reveal teleconnection patterns consistent with known patterns of ENSO variability. Significant correlated variability is observed near 15 year period, with the dominant tele‐connection pattern largely confined to the Northern Hemisphere. Peak‐to‐peak ΔT ≈0.5°, with simultaneous warming and cooling of discrete patches on the earth's surface. A global average of this pattern would largely cancel.