Abstract

  The corona is the Sun's outer atmosphere which is more than 100 times hotter than the solar photosphere. To understand how the observed coronal features form and evolve as the consequence of the energy input into the corona during magnetic flux emergence in the photosphere, we use the output of a magnetic flux emergence simulation to drive a magnetohydrodynamics (MHD) simulation for the corona. The proper treatment on the energy balance, as in the real corona, allows the model to synthesise EUV emission directly comparable to observations. 

  In the coronal model numerous bright coronal EUV loops form during the formation of a sunspot pair in the model photosphere. The thermal dynamics and energetics of the plasma in individual magnetic fieldlines are consistent with the expectation of traditional one dimensional loop models with prescribed heat input. An apparently static EUV structure is created by the plasma in the emerging magnetic fieldlines. The EUV spectral lines formed at transition region temperature (~ 100000 K) show blue shifts near their apex and red shifts at the footpoints. These results show essentially new view on the dynamics of the corona in an emerging active region, and emphasises the necessity of treating the plasma and the magnetic field at the same time, in order to self-consistently model dynamics of the coronal plasma.