Atmosphere above sunspots is abundant with different types of waves. Among these waves are running penumbral waves in the chromosphere, quasi-periodic...
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PublicationTracing p-mode Waves from the Photosphere to the Corona in Active Regions
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PublicationTurbulent Erosion of Magnetic Flux Tubes
Results from a numerical and analytical investigation of the solution of a nonlinear axisymmetric diffusion equation for the magnetic field are presented for...
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PublicationTwist, Writhe, and Helicity in the Inner Penumbra of a Sunspot
The aim of this work is the determination of the twist, writhe, and self-magnetic helicity of penumbral filaments located in an inner sunspot penumbra. For this...
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PublicationTwo magnetic components in sunspot penumbrae
The magnetic and kinematic configuration of sunspot penumbrae is investigated by performing an inversion of the Stokes profiles of three infrared lines at 1565...
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PublicationUmbral dots - A case of penetrative convection between sunspot fragments
A study of the observations made on the development and, in some cases, even the decay of 15 large active regions is presented. It is shown that the mature...
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PublicationUnusual Stokes V profiles during flaring activity of a delta sunspot
Aims: We analyze a set of full Stokes profile observations of the flaring active region NOAA 10808. The region was recorded with the Vector-Spectromagnetograph...
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PublicationUpper chromospheric magnetic field of a sunspot penumbra: observations of fine structure
Aims: The fine-structure of the magnetic field in a sunspot penumbra in the upper chromosphere is to be explored and compared to that in the photosphere...
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PublicationVariation in sunspot properties between 1999 and 2011 as observed with the Tenerife Infrared Polarimeter
Aims: We study the variation in the magnetic field strength and the umbral intensity of sunspots during the declining phase of the solar cycle No. 23 and in the...
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PublicationVariation in sunspot properties between 1999 and 2014
Aims: We study the variation in the magnetic field strength, area, and continuum intensity of umbrae in solar cycles 23 and 24. Methods: We analyzed a sample of...