The Global Range of the Stratospheric Decadal Wave. Part I: Its Association with the Sunspot Cycle in Summer and in the Annual Mean, and with the Troposphere

Abstract

The authors correlate the 23-yr series of reanalyzed 30-hPa heights and temperatures and 10-hPa heights with the 11-yr solar cycle for the summers of both hemispheres and for the annual mean. The size and spatial pattern of the correlations in the Northern Hemisphere are the same as those of the correlations computed with a nearly twice as long series from the Freie Universität Berlin: a belt of correlations that encircles the hemisphere in the outer Tropics?subtropics. The correlation pattern is similar in the Southern Hemisphere. The spatial distribution of correlations between 30-hPa temperatures and the solar cycle has the same configuration as the height correlations with the cycle. The largest temperature correlations move with the sun from one summer hemisphere to the other. The first eigenvector in a principal component analysis of the 30-hPa heights in summer and in the annual mean has the same shape as the above-mentioned pattern in the correlations between the stratospheric data and the 11-yr solar cycle. The EOF 1 explains 77% of the variance in summer on the Northern Hemisphere and 72% on the Southern Hemisphere, and the time series of its amplitude is dominated by a decadal wave in phase with the 11-yr sunspot cycle.