SUMER observations of the evolution and the disappearance of a solar prominence

The mechanisms that lead to the formation and the disappearance of prominen ces are poorly understood, at present. An arch-shaped prominence was observ ed with the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spe ctrometer on board the Solar and Heliospheric Observatory (SOHO) on 31 Marc h-1 April 1996. The observations were per-formed at three wave-bands in the Lyman continuum. Ten successive images were obtained at il l-minute time i ntervals. Based on computed models of Gouttebroze, Heinzel, and Vial (1993) , we have determined the temperature distribution of the prominence using t he intensity ratio of 876 Angstrom and 907 Angstrom. The observed time sequ ence shows that parts of the prominence disappear possibly by heating, whil e other parts exhibit heating and cooling with apparent outward motion. We model the heat input with the linearized MHD equations using a prescribed i nitial density and a broad-band spectrum of Alfven waves. We find a good qu alitative agreement with observations. In the model the prominence is heate d by the resonant absorption of Alfven waves with frequencies that match th e resonant condition for a particular flux tube structure that is determine d by the magnetic field topology and plasma density.