The Solar Chromosphere

Ca II H filtergram of a solar prominence.

Chromosphere is the pink layer we observed around the solar disk during the total solar eclipses. The chromospheric plasma has a typical temperature of about 10 kK where atoms like calcium and magnesium are singly ionized. Due to ionization of hydrogen in upper chromosphere, the temperature starts to rise sharply in transition region layer above chomosphere. the non-local thermodynamic equilibrium and low plasma-beta regime makes physical processes more complicated than the photosphere. as a result, chromosphere is the least understood layer of the solar atmosphere. You can find below examples of some of the papers we have published about chromospheric properties of quiet Sun and active regions.