On the anomalous abundances of the 20,000-200,000 K solar atmosphere above a sunspot

The EUV spectrum (1175-1710 A) of a sunspot is compared with the EUV spectrum of two nearby plage regions. The observations were obtained during the July 21, 1975 rocket flight of the Naval Research Laboratory High Resolution Telescope and Spectrograph (HRTS). It is shown that the silicon-to-carbon elemental abundance ratios in the 20,000-200,000 K temperature regions observed in the plage are enhanced by a factor of about 3 relative to the same ratios in the sunspot. By comparing lines from C II, Si II, and Si III with H I Ly-alpha and O I, it is shown that above active regions the abundance of ionized silicon is enhanced relative to its value in the photosphere.