Chromospheric fibrils
Error
Chromospheric fibrils above an active region
Swedish 1-m Solar Telescope
When observed in the H-alpha spectral line, the chromosphere reveals a very complex structure made up of elongated fibrils having different lengths and orientations. They are believed to trace magnetic field lines in the chromosphere. The longest fibrils are nearly horizontal and connect sunspots or plage regions of opposite polarity, often spanning large separations. They are rather static. Also, there are shorter, more vertical fibrils rooted in active region plage that show impressive dynamics, with swaying and rotational motions, and jets that push chromospheric plasma upwards. Both types of fibrils reveal the full complexity of the solar chromosphere, but we still do not know much about their properties, origin, and relation to the chromospheric magnetic field. The dynamics of the short fibrils, however, is consistent with the driver being photospheric oscillations that leak into the chromosphere through inclined magnetic structures. At chromospheric heights, they develop into shocks and produce their characteristic jet-like behavior.
The movie illustrates in a beautiful way the ever-changing chromospheric landscape in active regions, and particularly the continuous rise and fall of material in dynamic fibrils (best seen in the lower central part of the field of view).
To download the movie, click HERE
Movie credit: Michiel van Noort and Luc Rouppe van der Voort (ITA, University of Oslo)
Text credit: Luis Bellot Rubio (IAA-CSIC)
Source: SST Galleries