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The EUV Spectrum of Sunspot Plumes Observed by SUMER on SOHO

Dwivedi, B. N.; Curdt, W.; Feldman, U.

We present results from sunspot observations obtained by SUMER on SOHO. In sunspot plumes the EUV spectrum differs from the quiet Sun; continua are observed with different slopes and intensities; emission lines from molecular hydrogen and many unidentified species indicate unique plasma conditions above sunspots. Sunspot plumes are sites of system…

Electron Density and Temperature Measurements, and Abundance Anomalies in the Solar Atmosphere

Landi, Enrico; Dwivedi, Bhola N.; Mohan, Anita

Using spectra obtained from the SUMER (Solar Ultraviolet Measurements of Emitted Radiation) spectrograph on the spacecraft SOHO (Solar and Heliospheric Observatory), we investigate the height dependence of electron density, temperature and abundance anomalies in the solar atmosphere. In particular, we present the behaviour of the solar FIP effect …