The result of a T-mode Canonical Components Analysis (CCA) of monthly anomalies in sea surface temperature versus monthly anomalies in lower tropospheric temperature from 1982-2010. Traditional S-mode CCA looks for recurrent temporal patterns across the two data series. In T-mode analysis, it is looking for recurrent spatial patterns. In this global analysis, it turns out that the predominant global spatial pattern is that of the Pacific Decadal Oscillation (PDO). In the graph, the index to PDO published by NOAA is plotted (in green) on top of the X-variate (sea-surface temperature) homogenous correlation (in blue). The correlation is 0.80. An equivalent S-mode CCA finds that the familiar ENSO (El Niño Southern Oscillation) pattern is the most prevalent pattern over time.