Fig. 18

Synchronisation between stations CNST and PAWA (see Fig. 11a). a Cross recurrence plot between CNST_e (bottom trace) and PAWA_e (top trace). The plot shows lines of synchronisation (LOS) in darkest blue. The red arrows indicate some areas where the ratio of the frequencies of the two signals increases to a large number. The white arrows mark black areas corresponding to no synchronisation. b Joint recurrence plot between CNST_e (bottom trace) and PAWA_e (top trace). The plot shows strong synchronisation of recurrences in the two signals especially along the main diagonal. c, d Plots of log(percent cross recurrences) versus log(1/lag) for CNST_e and PAWA_e respectively. e Logarithm of normalised joint recurrence against logarithm of frequency for CNST_e and PAWA_e