Heating of the outer solar atmosphere
A clear understanding of the mechanisms of energy release at the coronal level requires a determination of the localisation in the coronal magnetic structures, and the temporal profile of the processes of dissipation of energy in the plasma, and possibly related turbulent and hydrodynamical phenomena. This remains an open problem. An important contribution to the solution of this problem is provided by the development of hydrodynamical models that include the more convincing modes of plasma heating, in order to carry out numerical simulations of the coronal magnetic structures and predicted EUV and X-ray emission. Another fundamental ingredient in this context is the determination of the chemical composition of the corona, in particular the abundance of helium, and any evidence for differences between coronal regions with different magnetic configurations. In the field of coronal studies, Italy has consolidated an undisputed leadership role over recent decades, with the building of the UVCS spectrometer that
has worked superbly aboard SOHO for over 13 years. The experience gained with UVCS allows the Italian community to give a significant contribution to the scientific problems connected to the solar corona, and to take a proactive role which allows: the construction of the HERSCHEL/SCORE coronograph, construction of the polarimetric system for the ultraviolet coronograph "Lyot" for the SMESE mission (CNES – Chinese Space Agency), to propose a coronograph for the SOLAR ORBITER for white light and UV images ofthe extended corona for high resolution study of the source regions of the solar wind and the dynamics of Coronal Mass Ejections (CME), together with a very high resolution EUV spectrometer and EUV spectrocoronograph for the study of the extended corona at small heliocentric distances. Participation in the ASPIICS (Association de SatellitesPour l’Imagerie et l’Interferometrie de la Couronne Solare), proposed by ESA as part ofthe PROBA-3 programme, and which uses an externally occulted coronograph, is also foreseen. The Italian solar space community is also studying the coronograph that will flyon the KUAFU mission (Chinese Space Agency) that will primarily be concerned with the monitoring of space weather and prediction of the effects on the Earth.
