DOT high-resolution imagery suggests that only internetworkspanning Hα “mottles” constitute the quiet-sun chromosphere, whereas more upright network “straws” in “hedge rows” reflect transition-region conditions.

The solar chromosphere is very dynamic, due to the presence of large amplitude hydrodynamic waves. Their propagation is affected by NLTE radiative transport in strong spectral lines, which can in turn be used to diagnose the dynamics of the chromosphere. We give a basic introduction into the equations of NLTE radiation hydrodynamics and describe how they are solved in current numerical simulati...

It is shown that a generalized magneto–Bernoulli mechanism can effectively generate high velocity flows in the Solar chromosphere by transforming the plasma pressure energy into kinetic energy. It is found that at reasonable heights and for realistic plasma parameters, there is a precipitous pressure fall accompanied by a sharp amplification of the flow speed. Subject headings: Sun: atmosphere ...

Aims. Our aim is to detect the mesogranulation structures at the upper solar chromosphere Methods. We have analyzed a time series of spectra in the hydrogen Lyman lines and the Lyman continuum obtained by the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectrometer on the SOlar Heliospheric Observatory (SOHO). The time series of about 2 hours and 22 minutes was obtained on 1999 ...