Aims: We investigate the impact on Fe abundance determination of including magnetic flux in series of 3D radiation-magnetohydrodynamics (MHD) simulations of solar convection, which we used to synthesize spectral intensity profiles corresponding to disc centre. Methods: A differential approach is used to quantify the changes in theoretical

Although over centennial and greater timescales solar variability may be one of the most influential climate forcing agents, the extent to which solar activity influences climate over shorter time periods is poorly understood. If a link exists between solar activity and climate, it is likely via a mechanism connected to one (or a combination) of

Low degree l=0-2 solar p-modes were detected with the SLOT instruments at Izana and Baja California. The main source of noise for these ground based observations is in the terrestrial atmosphere. However, the data acquisition system still has to have very low intrinsic noise. It is shown how this is achieved in the SLOT instruments. Design and

Since 1984 the measurements of a quadruple photometer sited at the Observatorio del Teide (Izana, Tenerife) made it possible to identify the p-mode luminosity spectrum with simultaneous velocity observations. Comparing this data, the adiabatic behavior of solar atmosphere and theoretical expectations from solar models were tested. In order to

An overall view of the solar surface is presented with emphasis on the study of low 1 value oscillations. Line of sight velocity measurements of the whole solar disk were made using optical resonance spectroscopy. Constancy of the peak of spectral emission is demonstrated in two ways; first, the observed peaks in the power spectra are numbered

Here we will present some spectroscopic methods for emission gas research in the emission line region of Active Galactic Nuclei (AGNs): (1) We will demonstrate the possibility to use the Boltzmann-plot method to estimate the physical conditions in the broad line regions (BLRs) (2) We will discuss the applicability of so called ``Gaussian method''