Propagating magneto-acoustic waves in the solar chromosphere

We report on spectroscopic one dimensional observations showing for the first time upward propagating 5 mn period waves, which emerge from the deep chromospheric network. Wavetrains are well measured at the height where the He I line (at lambda = 1083 nm) is formed by the coronal back radiation. We also present results from a time series of narrow filtergrams of a, quiet region at the disk center. The two dimensional mapping of the power of waves observed in the chromosphere shows the familiar cell-like distribution corresponding to the network magnetic field pattern. In addition, Fourier components with significantly longer periods than 5 mn were detected in the chromospheric network. We suggest that the waves propagating in the open corona are reminescent of photospheric oscillations transmitted by the magnetic field of the chromospheric network.