  In this work, we present a study of the propagation of low-frequency
magneto-acoustic waves into the solar chromosphere within small-scale inclined
magnetic fields over a quiet-magnetic network region utilizing
near-simultaneous photospheric and chromospheric Dopplergrams obtained from the
HMI instrument onboard SDO spacecraft and the Multi-Application Solar Telescope
(MAST) operational at the Udaipur Solar Observatory, respectively. Acoustic
waves are stochastically excited inside the convection zone of the Sun and
intermittently interact with the background magnetic fields resulting into
episodic signals. In order to detect these episodic signals, we apply the
wavelet transform technique to the photospheric and chromospheric velocity
oscillations in magnetic network regions. The wavelet power spectrum over
photospheric and chromospheric velocity signals show a one-to-one
correspondence between the presence of power in the 2.5-4 mHz band. Further, we
notice that power in the 2.5-4 mHz band is not consistently present in the
chromospheric wavelet power spectrum despite its presence in the photospheric
wavelet power spectrum. This indicates that leakage of photospheric
oscillations (2.5-4 mHz band) into the higher atmosphere is not a continuous
process. The average phase and coherence spectra estimated from these
photospheric and chromospheric velocity oscillations illustrate the propagation
of photospheric oscillations (2.5-4 mHz) into the solar chromosphere along the
inclined magnetic fields. Additionally, chromospheric power maps estimated from
the MAST Dopplergrams also show the presence of high-frequency acoustic halos
around relatively high magnetic concentrations, depicting the refraction of
high-frequency fast mode waves around vA ~ vs layer in the solar atmosphere.

Solar and Stellar Astrophysics