Coronal plasmoid dynamics II. The nonstationary fine structure

We analyze the non-uniform motion of a white light coronal plasmoid of 1.5 Mm in diameter, which has been followed at the prime focus of the Canada-Fr ance-Kawaii Telescope (CFHT) during the July 11, 1991 total solar eclipse. Two possibilities are considered to explain the acceleration of the plasmoi d by the magnetic force: large amplitude oscillations and the rotation of t he plasmoid magnetic dipole about the external inhomogeneous magnetic field vector. We then describe for the first time the fine structure of the plas moid, its splitting and its interaction with the surrounding thread-like co ronal structures. The smallest-scale inhomogeneities (knots inside the plas moid) have a characteristic length of about 400 km. The observed complex be haviour of these plasma objects leads us to conclude that existing models o f mass supply to the corona by expanding plasmoids and their input into the process of the solar wind acceleration seem to be oversimplified, mainly b ecause the fine structure and the turbulent intermixing have not been reali stically taken into account. We also conclude on the importance of dynamica l processes at the smallest scales coronal structures when the heating prob lem is considered.