Abstract:
Solar eclipses established the existence of the outer region of the solar atmosphere, the solar corona, extending to several solar-radii and exhibiting open and closed magnetic field patterns. The density and the temperature of the solar corona were inferred from the optical spectrum. Through the use of coronagraphs on and above the earth and finally on the skylab and with enlarged range of spectral, spatial and temporal resolutions, a multitude of structures formed by the complex intraplay of density, temperature and magnetic field gradients, have been revealed. The morphology and dynamics of these structures which set up a link between the interior of the sun and the solar wind, are briefly described in this review.