Hierarchy of chromospheric structures and their relation to the magnetic field
Abstract
While the plasma is dominating the magnetic field in the photosphere, the roles are exchanged in the corona. In a "traditional" one-dimensional picture the change from plasma to magnetically dominated (at plasma β = 1) takes place somewhere in the chromosphere. Therefore the magnetic structure of the chromosphere is one of the keys to understand the relevant processes in the solar atmosphere. The most prominent structure of the chromosphere is the network with strong magnetic fields. The interior of the super-granulation cells are non-magnetic and dominated by shocks producing the well known grains. The oscillations can be heavily influenced by the magnetic structure: e.g. in case of a low canopy the usually prominent 3 minute intensity fluctuations might vanish. The structure of the network, however, is far more complicated. A large number of phenomena, spicules being the most prominent one, are found in the network. While the chromospheric structures in the visible and near UV are now studied for more than 100 years, it was not until recently that also the EUV emission lines and continua from the chromosphere can be studied. Furthermore EUV images in lines formed at coronal temperatures revealed new chromospheric phenomena, like the "moss", and their relation to the "classical" chromosphere is still unclear. This paper will try to review (some of) the important chromospheric structures and discuss their relation to photospheric and coronal processes, especially with respect to the magnetic field.
- Publication:
-
SOLMAG 2002. Proceedings of the Magnetic Coupling of the Solar Atmosphere Euroconference
- Pub Date:
- October 2002
- Bibcode:
- 2002ESASP.505..155P
- Keywords:
-
- Sun: Chromosphere;
- Sun: Magnetic Field