Fig. 7From: Automatic selection of Dst storms and their seasonal variations in two versions of Dst in 50 yearsWavelet amplitude spectra of the number of storms in solar cycles 19–23 (12 × 5 data points of 1 month resolution); color scale gives amplitude in units of number of storms, white lines indicate cone of confidence and black and purple curves represent 95 and 98% significant levelsBack to article page