Multimode Quasiperiodic Pulsations in Extreme-ultraviolet Emissions Associated with an X-Class Solar Flare
Year: 2026
Type: article
Abstract: We report detection of quasi-periodic pulsations in extreme-ultraviolet (EUV) emissions during the peak phase of an X-class solar flare. Temporal variation of EUV intensity in 171 Å and 335 Å channels of SDO/AIA were analyzed using wavelet transform, Ensemble Empirical Mode Decomposition (EEMD), Hilbert–Huang spectral analysis, and Fourier techniques to investigate properties of oscillation modes. During the impulsive phase, wavelet spectra showed statistically significant power enhancements, exhibiting a dominant periodicity of 146 ± 18 s in AIA 171 Å and 186 ± 18 s in AIA 335 Å. EEMD results indicate the second and third intrinsic mode functions (IMFs) represent these periodicities too, whereas higher-order modes correspond to long-term background variations. Hilbert spectral analysis identifies periods of 117 s and 197 s in AIA 171 Å, and 125 s and 194 s in AIA 335 Å too, respectively. It is noteworthy that wavelet and EEMD emphasize different features, transient power versus intrinsic mode decomposition, yet their consistency in the 2–3 minute range strengthens the robustness of detected oscillatory patterns. Moreover, Hilbert spectra reveal pronounced nonstationarity and amplitude modulation, accounting for discrepancies with global Fourier estimates. Reconstructed IMFs, with cross-correlation coefficient ∼0.9 relative to original light curves, confirm the multiperiodic nature of quasiperiodic pulsations. These findings suggest coexistence of 2 and 3 minute oscillations are intrinsic to the emission of this flare, implying the operation of multimodal processes in coronal energy release.
Source: The Astrophysical Journal
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
OpenAlex ID: W7161274534