Figure 3

Wavelet coherence and phase analyses of meningitis time series between countries. The left or top panel represents the wavelet coherence (x-axis: year, y-axis: period, in years). Blue, low coherence; red, high coherence. The dotted lines show the a = 5% and a = 10% significance levels based on 500 bootstrapped series. The cone of influence (black curve) indicates the region not influenced by edge effects. The right or bottom panels represent the phase analyse between two countries (in blue and red), based on wavelets for a given periodic band (white band). Green boxes represents the period of time where coherency is significant, i.e. when the interpretation of analyse is possible. Blue lines: first country (name in blue); red lines: second country (name in red); dashed lines: time delay between the two oscillating components (?T).