Global solar oscillations below the acoustic cut-off frequency are trapped within the solar interior and become resonant. Signatures of these oscillations persist above the acoustic cut-off frequency, and these travelling waves are known as pseudomodes. Acoustic oscillation frequencies are known to be correlated with the solar cycle, but the pseudomode frequencies are predicted to vary in anti-phase. Therefore, pseudomodes can provide further insight into the Sun’s magnetic activity cycle. We analyze Global Oscillation Network (GONG) data covering two solar cycles (1996- 2017) by splitting them into overlapping 36-day long segments. The frequency shifts are then calculated via cross-correlating the segments’ power spectra. In agreement with previous studies, we find that the pseudomode frequency variations are in anti-phase with the solar cycle. Furthermore, the pseudomode frequency shifts show a double-peak feature at their maximum, which corresponds to solar activity minimum, and is not seen in the solar proxies. The auto-correlation was computed for the pseudomode range of 5600 − 8000μHz for GONG time series data from 1 January 2001 to 11 March 2021.

Slow magnetoacoustic waves can occur in hot coronal loops. By using previously published SUMER and sloshing events data, the scalings with temperature of the oscillation periods, decay times, and amplitudes are calculated using MCMC and Bayesian inference fitting methods. The time evolution of spatial harmonics for each sloshing event is also investigated. The damping time is found to be almost linearly scaled to the period of oscillation. These results show a potential competition of nonlinear and dissipative effects.