While sunspots are easily observed at the solar surface, determining their subsurface
structure is not trivial. There are two main hypotheses for the subsurface structure of …

Waves observed in the photosphere and chromosphere of sunspots show complex
dynamics and spatial patterns. The interpretation of high-resolution sunspot wave …

A number of fundamental questions as regards the physical nature of sunspots are
formulated. In order to answer these questions, we apply the model of a round-shaped …

Magnetic fields extend from the solar interior through the atmosphere. The formation and
evolution of active regions can be studied by measuring subsurface flows with local …

Waves are observed at all layers of the solar atmosphere and the magnetic field plays a key
role in their propagation. While deep down in the atmosphere the p-modes are almost …

One goal of helioseismology is to determine the subsurface structure of sunspots. In order to
do so, it is important to understand first the near-surface effects of sunspots on solar waves …

Aims. We analyse numerically the propagation and dispersion of acoustic waves in the solar-
like sub-photosphere with localised non-uniform magnetic field concentrations, mimicking …

This chapter brings together two of the prominent features of our star the Sun: its well‐
developed p‐mode spectrum of global oscillations excited by near‐surface convection, and …

Wave propagation through sunspots involves conversion between waves of acoustic and
magnetic character. In addition, the thermal structure of sunspots is very different than that of …

We investigate deviations in the mean phase travel time of acoustic waves preceding the
emergence of 46 large active regions observed by the Helioseismic and Magnetic Imager. In …