High-resolution white light and H-alpha observations are used to study the development of 15 large active solar regions. The behavior of the magnetic fragments...

Data obtained at the Observatorio del Teide (Tenerife) during the years 1978 to 1988 using a resonant scattering spectrophotometer, is analyzed to look for...

We present a consistent model of storage, instability and dynamical eruption of magnetic flux tubes in the solar convection zone and underlying overshoot region...

Catalogues and other records of aurora-borealis events were used to study the long-term spatial and temporal variation of these phenomena in the period from...

The long-term spatial and temporal variation of aurora borealis events from 1600 to the present were studied using catalogues and other records of these...

We show that cyclic activity and Maunder-type grand minima can be explained by a dynamo driven by the instability of magnetic flux tubes in the overshoot layer...

It has been known since the work by Claverie et al. (1982) that integrated-sunlight velocities measured with the resonance scattering technique show variations...