Panels a–c: results of the wavelet and Fourier analyses of the soft X-ray, microwave, and Hα R4 kernel data, during the decay flare phase. Panel d: empirical mode decomposition (EMD) spectrum of the microwave flux at 5.7 GHz. The total energies of the decomposed intrinsic modes are shown by crosses. The blue curve represents the global slope of the spectrum. The 99% confidence intervals are shown by red curves.