THE SUNSPOT TRANSITION REGION - WHERE ARE THE BRIGHT PLUMES AND THE DOWNFLOWS

Measurements of umbral-to-quiet Sun and umbral-to-plage contrast in five active regions have been obtained in the transition region emission lines Si IV lambda1402.77, C IV lambda1548.19, and 0 V 1371.29 using the Ultraviolet Spectrometer and Polarimeter (UVSP) on the Solar Maximum Mission. The umbral transition region in these lines appears generally indistinguishable from the quiet transition region. In addition, high-resolution profiles of the C IV lines lambdalambda1548.19, 1550.77 in the umbrae of eight individual sunspots in different active regions show only weak, mostly subsonic, redshifted components. This result differs sharply from the observations of multiple, strong, often supersonic downflows observed with the HRTS instrument (e.g., Brekke et al.).