ON THE ANOMALOUS ABUNDANCES OF THE 2 X 10(4)-2 X 10(5)-K SOLAR ATMOSPHERE ABOVE A SUNSPOT

The EUV spectrum (1175-1710 Å) of a sunspot is compared with the EUV spectrum of two nearby plage regions. The observations were obtained during the 1975 July 21 rocket flight of the Naval Research Laboratory High Resolution Telescope and Spectrograph (HRTS). We show that the silicon-to-carbon elemental abundance ratios in the 2 × 104-2 × 105 K temperature regions observed in the plage are enhanced by a factor of ∼ 3 relative to the same ratios in the sunspot. By comparing lines from C II, Si II, and Si III with H I Lyα and O I, we show that above active regions the abundance of ionized silicon is enhanced relative to its value in the photosphere. The behavior of the He II 1640 Å line between plage and sunspot is similar to that of C IV 1550 Å, while the S IV 1406 Å line behavior is intermediate between Si IV 1403 Å and C IV 1550 Å We conclude by showing that the elemental abundances observed in the atmosphere above the sunspot resemble a photospheric distribution and therefore that the elemental selection mechanisms which produce "coronaltype" abundances in the outer atmosphere of the Sun do not operate effectively over the sunspot.