Wavelet analyses of periodicity of the two sets of lobster data.

<p><b>a</b>) displays the wavelet power spectrum of the SREAS data where the dominant periodicity of ∼20 years becomes less pronounced as well as shorter through the time series. The color symbolizes the strength of the periodicity. Blue is weak, red is strong and contours indicate statistically significant periodicities. The cone of influence is drawn and suggests that any periods above are doubtful due to time series length. <b>b</b>) displays the global wavelet spectrum and the dotted line shows the corresponding confidence interval indicating the significance of the periodicities. <b>c</b>) and <b>d</b>) are the global power spectrum and the wavelet power spectrum of the VCD data respectively, showing no significant periodicity.