Mats Carlsson

NameMats Carlsson
AffiliationRosseland Centre for Solar Physics, University of Oslo, Norway
TitleModelling of the Solar Chromosphere
AuthorsMats Carlsson
AbstractThe chromosphere is arguably the most difficult and least understood domain of solar physics. All at once it represents the transition from optically thick to thin radiation escape, from gas-pressure domination to magnetic-pressure domination, from neutral to ionised state, from MHD to plasma physics, and from near-equilibrium ("LTE") to non-equilibrium conditions. The heating requirements of the solar chromosphere are not easily determined since the radiative cooling is dominated by optically thick spectral lines that form far from equilibrium. Energy estimates are therefore very model dependent. 1D semi-empirical model atmospheres indicate that to maintain the quiet, average solar chromosphere, the required energy input is in the range 2-12 kW/m2 but these models neglect many important aspects like the dynamics of the chromosphere, non-equilibrium ionization effects and spatial structuring. In this talk we will review the modelling of the Solar Chromosphere - from 1D semi-empirical models to 3D radiation magnetohydrodynamic models with increasing level of realism in the physical approximations.