Investigating the reliability of the assumption of instantaneous chemical equilibrium (ICE) for calculating the CO number density in the solar atmosphere is of crucial importance for the resolution of the long-standing controversy over the existence of ‘cool clouds’ in the chromosphere, and for determining whether the cool gas owes its existence to CO radiative cooling or to a hydrodynamical pr...

Emission lines from the solar transition region between the chromosphere and the corona often show a two Gaussian component profile with a core and a broad second component contributing up to 25% to the total intensity. For the first time a systematic study of the broadening and Doppler shift of the second weaker components is performed using SUMER on SOHO to explore the spatial structures of t...

The Solar Mean Magnetic Field (SMMF) is the mean value of line sight (LOS) component solar vector magnetic field averaged over visible hemisphere Sun. So far, studies on SMMF have mostly been confined to measurements at photosphere. In this study, we calculate and analyse using chromosphere, in conjunction with that photospheric measurements. For purpose, used full disk LOS magnetograms derived...