Features of synchronization of hemispheric variations of temperature at decadal scale using data of instrumental observations and simulation data of the INM RAS climate model
Using the technique of wavelet cross-correlations, the features of hemispheric variations in surface air temperature are considered. The variations are presented in the time series of instrumental meteorological observations from the end of the 19th century to the present. The phase synchronization of these variations is found on the time scales of one, two, and six to seven decades. Such synchronization is not seen on intermediate time scales, where the amplitudes of the variations are smaller. A comparison of the hemispheric temperature variations in the long integration of the climatic model of the Institute of Computational Mathematics of the Russian Academy of Sciences (pi-Control experiment, when external forcing was taken equal to their mean values over the pre-industrial period) did not show such synchronization. However, in historical experiment, in which the quasiperiodic changes in the incoming solar radiation flux modulated by solar activity were taken into account, the phase synchronization was detected on a two-decade scale. This allows to hypothesize that very small periodic changes in external forcing of the climate system may play an important role in the formation of temperature variations’ spectrum within considered range of scales (from a year to half a century).