All of the WASEM spectra are based on the wavelet analysis techniques.

There is used the Morlet wavelet power spectrum (Torrence & Compo 1998) for our analysis. The confidence level relative to red noise was taken into account and the solid contour around the tadpole patterns shows the 99% confidence level. Thus, we only studied the most dominant characteristic wavelet signatures.

The wavelet spectra were plotted with the lighter areas indicating the greater power. The region under curves in the wavelet power spectra belongs to the cone of influence (COI) where edge eects can become important as a result of dealing with finite-length time series. Wavelet parameter omega was set to 6, that is, we preferred to specify an exact period rather than an exact time interval.

Newly reconstructed e.g., space-time diagrams with the separated individual plasma flows or tadpole waves etc. were computed with the help of the inverse wavelet analysis (Torrence & Compo 1998) for individual period ranges. The positive and negative parts of the amplitudes in these new diagrams (in relation to their mean values) are given in white and black, respectively.

If the selected time series displayed a background continuum and its wavelet power spectrum did not have any relevant periodicities then these separated space-time diagrams can belong to the steady plasma emission.