Can major solar flares excite high-frequency global waves in the Sun ?

TL;DR

This study investigates whether major solar flares can excite high-frequency global waves in the Sun by analyzing velocity data from SOHO instruments, revealing a clear enhancement in MDI data but only a weak effect in GOLF data.

Contribution

It provides new evidence of flare-induced high-frequency wave excitation in the Sun using wavelet and Fourier analysis of velocity observations.

Findings

High-frequency waves are enhanced during the flare in MDI data.

GOLF data shows only a feeble effect of the flare on high-frequency oscillations.

Wavelet analysis effectively detects flare-related wave enhancements.

Abstract

The study of low-degree high-frequency waves in the Sun can provide new insight into the dynamics of the deeper layers of the Sun. Here, we present the analysis of the velocity observations of the Sun obtained from the Michelson and Doppler Imager (MDI) and Global Oscillations at Low Frequency (GOLF) instruments on board Solar and Heliospheric Observatory (SOHO) spacecraft for the major flare event of 2003 October 28 during the solar cycle 23. We have applied wavelet transform to the time series of disk-integrated velocity signals from the solar surface using the full-disk Dopplergrams obtained from MDI. The wavelet power spectrum computed from MDI velocity series clearly shows that there is enhancement of high-frequency global waves in the Sun during the flare. We do observe this signature of flare in the Fourier Power Spectrum of these velocity oscillations. However, the analysis of disk-integrated velocity observations obtained from GOLF shows only feeble effect of flare on high-frequency oscillations.