  We present a new insight into the propagation of ion magnetoacoustic and
neutral acoustic waves in a magnetic arcade in the lower solar atmosphere. By
means of numerical simulations, we aim to: (a) study two-fluid waves
propagating in a magnetic arcade embedded in the partially-ionized, lower solar
atmosphere; and (b) investigate the impact of the background magnetic field
configuration on the observed wave-periods. We consider a 2D approximation of
the gravitationally stratified and partially-ionized lower solar atmosphere
consisting of ion+electron and neutral fluids that are coupled by ion-neutral
collisions. In this model, the convection below the photosphere is responsible
for the excitation of ion magnetoacoustic-gravity and neutral acoustic-gravity
waves. We find that in the solar photosphere, where ions and neutrals are
strongly coupled by collisions, ion magnetoacoustic-gravity and neutral
acoustic-gravity waves have periods ranging from 250 s to 350 s. In the
chromosphere, where the collisional coupling is weak, the wave characteristics
strongly depend on the magnetic field configuration. Above the foot-points of
the considered arcade, the plasma is dominated by a vertical magnetic field
along which ion magnetoacoustic-gravity waves propagate. These waves exhibit a
broad range of periods with the most prominent periods of 180 s, 220 s, and 300
s. Above the main loop of the solar arcade, where mostly horizontal magnetic
field lines guide ion magnetoacoustic-gravity waves, the main spectral power
reduces to the period of about 180 s and longer wave-periods do not exist. Our
results are in agreement with the recent observational data reported by
Wi\'sniewska et al. (2016) and Kayshap et al. (2018).
