  We study the TR properties above sunspots and the surrounding plage regions,
by analyzing several sunspot spectra obtained by SUMER in March 1999 and
November 2006. We compare the SUMER spectra observed in the umbra, penumbra,
plage, and sunspot plume regions. The Lyman line profiles averaged in each
region are presented. For the sunspot observed in 2006, the electron densities,
DEM, and filling factors of the TR plasma in the four regions are also
investigated. The self-reversals of the Lyman line profiles are almost absent
in umbral regions at different locations (heliocentric angle up to $49^\circ$)
on the solar disk. In the sunspot plume, the Lyman lines are also not reversed,
whilst the lower Lyman line profiles observed in the plage region are obviously
reversed. The TR densities of the umbra and plume are similar and one order of
magnitude lower than those of the plage and penumbra. The DEM curve of the
sunspot plume exhibits a peak centered around $\log(T/\rm{K})\sim5.45$, which
exceeds the DEM of other regions by one to two orders of magnitude at these
temperatures. We also find that more than 100 lines, which are very weak or not
observed anywhere else on the Sun, are well observed by SUMER in the sunspot,
especially in the sunspot plume. We suggest that the TR above sunspots is
higher and probably more extended, and that the opacity of the hydrogen lines
is much smaller above sunspots, as compared to the TR above plage regions. Our
result indicates that the enhanced TR emission of the sunspot plume is very
likely to be the result of a large filling factor. The strongly enhanced
emission at TR temperatures and the reduced continuum make many normally weak
TR lines stick out clearly in the spectra of sunspot plumes.
