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Article
Symmetries, first integrals and splittability of dynamical systems
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Article
Geometrical foundations and results on a problem suggested in a paper by Andersonet al.
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Chapter and Conference Paper
Observations of the birth and fine structure of sunspot penumbrae
High resolution white-light pictures of sunspot penumbrae are presented. These include pictures showing details of their filamentary structure and some instances of birth of a penumbra. The observations are di...
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Article
Decay rates of sunspot groups from 1874 to 1976
The global behaviour and fine structure of the distribution of sunspot decay rates from activity cycle 13 to 20 are presented. It is shown that the distribution of this parameter is lognormal. Statistically si...
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Chapter
The Motion of Magnetic Flux Tubes in the Convection Zone and the Subsurface Origin of Active Regions
The rise of kink-unstable magnetic flux tubes through the solar convection zone is discussed with a view to explaining the subsurface origin of active regions. In spite of the advances and insights obtained by...
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Chapter and Conference Paper
Storage of Magnetic Flux in the Overshoot Region
The combined action of the subadiabatic ambient stratification in the overshoot region below the convection zone and the inertial forces associated with the solar rotation is shown to lead to the suppression o...
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Chapter
Dynamics of Erupting Magnetic Flux Tubes
The eruption of magnetic flux tubes from the overshoot layer due to instability and the dynamics of their subsequent rise through the solar convection zone are followed by numerical simulation. Special emphasi...
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Article
Active region asymmetry as a result of the rise of magnetic flux tubes
The magnetic flux tubes that rise across the convection zone to produce active regions are shown to develop a difference in inclination between their preceding and follower sides. This asymmetry is such that t...
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Chapter
The Emergence of Magnetic Field into Stellar Atmospheres
The magnetic activity in the atmosphere of the Sun, possibly of most other magnetically active late-type stars, is a consequence of the emergence of magnetic flux from the stellar interior. Research in this fi...
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Article
The Emergence of Magnetic Field into Stellar Atmospheres
The magnetic activity in the atmosphere of the Sun, possibly of most other magnetically active late-type stars, is a consequence of the emergence of magnetic flux from the stellar interior. Research in this fi...
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Article
Solar Coronal Jets: Observations, Theory, and Modeling
Coronal jets represent important manifestations of ubiquitous solar transients, which may be the source of significant mass and energy input to the upper solar atmosphere and the solar wind. While the energy i...