Observations of the solar chromosphere are often interpreted using methods derived from static modeling (e.g., the Vernazza et al. 1981 model atmospheres and work based on such models) or linear theory (e.g., phase relations). Recent numerical simulations have shown that such an analysis can be very misleading. It is found that enhanced chromospheric emission, which corresponds to an outwardly ...

We analyze the important formation processes for the Mg I 457.1 nm line. This line is an intercombination line and the source function is close to the local thermodynamic equilibrium (LTE) value. The strong coupling to the local temperature and the relatively high population of the lower level (the ground state of Mg I) makes this line an ideal candidate for temperature diagnostics in the lower...

Linear eigenmodes are determined for the solar atmosphere in the presence of a gravitational field and a magnetic field. The atmosphere consists of a horizontal nonuniform chromosphere and a semi-infinite nonuniform corona. It is bounded from below by a heavy and immovable photosphere. Inhomogeneity is confined to the vertical direction. The gravitational acceleration is constant and the equili...

Aims. We investigate the oscillatory properties of the quiet solar chromosphere in relation to the underlying photosphere, with particular regard to the effects of the magnetic topology. Methods. For the first time we perform a Fourier analysis on a sequence of line-of-sight velocities measured simultaneously in a photospheric (Fe I 709.0 nm) and a chromospheric line (Ca II 854.2 nm). The veloc...

By use of the high-resolution spectral data obtained with THEMIS on 2002 September 5, the characteristics of 14 well-observed Ellerman bombs (EBs) have been analyzed. Our results indicate that 9 of the 14 EBs are located near the longitudinal magnetic polarity inversion lines. Most of the EBs are accompanied by mass motions. The most obvious characteristic of the EB spectra is the two emission ...

Context. The continuum intensity at wavelengths around 1 mm provides an excellent way to probe the solar chromosphere and thus valuable input for the ongoing controversy on the thermal structure and the dynamics of this layer. Aims. The synthetic continuum intensity maps for near-millimetre wavelengths presented here demonstrate the potential of future observations of the small-scale structure ...