Astrophysical: Sunspots

  • Publication
    Magnetic fields of opposite polarity in sunspot penumbrae
    Context. A significant part of the penumbral magnetic field returns below the surface in the very deep photosphere. For lines in the visible, a large portion of...
  • Publication
    Magnetic Flux Cancellation in the Moat of Sunspots: Results from Simultaneous Vector Spectropolarimetry in the Visible and the Infrared
    We analyze multiwavelength observations of the cancellation of a moving magnetic feature and a plage element at the outer edge of the moat of an isolated, round...
  • Publication
    Magneto-acoustic Waves in Sunspots: First Results From a New Three-dimensional Nonlinear Magnetohydrodynamic Code
    Waves observed in the photosphere and chromosphere of sunspots show complex dynamics and spatial patterns. The interpretation of high-resolution sunspot wave...
  • Publication
    Magnetoacoustic Wave Energy from Numerical Simulations of an Observed Sunspot Umbra
    We aim at reproducing the height dependence of sunspot wave signatures obtained from spectropolarimetric observations through three-dimensional MHD numerical...
  • Publication
    Magnetoacoustic Waves in Sunspots
    Observed variations of the magnetic field strength in sunspot umbrae consist of intrinsic oscillations and ``false'' oscillations due to time-dependent opacity...
  • Publication
    Magnetohydrostatic Sunspot Models from Deep Subphotospheric to Chromospheric Layers
    In order to understand the influence of magnetic fields on the propagation properties of waves, as derived from different local helioseismology techniques...
  • Talk
    Mapping the Sun's upper photosphere with artificial neural networks
    In this talk I'll present results from a recent paper in which we have developed a new analysis technique for solar spectra based on artificial neural networks...
  • Publication
    Methodology for Predicting the Probability Distribution of the Amplitude of Solar Cycle 25
    A number of precursor-type methods for solar-cycle prediction are based on the use of regression models and confidence-level estimates. A drawback of these...
  • Publication
    Moat Flow in the Vicinity of Sunspots for Various Penumbral Configurations
    High-resolution time series of sunspots have been obtained with the Swedish 1 m Solar Telescope between 2003 and 2006 at different locations on the solar disk...