Small-scale structure and dynamics of the chromospheric magnetic field

Sven Wedemeyer-Böhm

Published 2009-11-30Version 1

Recent advances in observational performance and numerical simulations have revolutionised our understanding of the solar chromosphere. This concerns in particular the structure and dynamics on small spatial and temporal scales. As a result, the picture of the solar chromosphere changed from an idealised static and plane-parallel stratification to a complex compound of intermittent domains, which are dynamically coupled to the layers below and above. In this picture, the chromosphere in a stricter sense is associated with the typical fibrillar structure shaped by magnetic fields like it is known from images taken in the H alpha line core. In internetwork regions below this layer, there exists a domain with propagating shock waves and weak magnetic fields, which both probably interact with the overlying large scale field. The existence of such a sub-canopy domain certainly depends on the properties of the overlying field. Details of the structure of the lower atmosphere can therefore be expected to vary significantly from location to location. Here, high-resolution observations, which were obtained with the CRISP filter at the Swedish Solar Telescope, are used to derive qualitative constraints for the atmospheric structure of quiet Sun regions.