This image shows UVCS/SOHO observations of the O VI 1032 and 1037
Angstrom line profiles in four types of coronal structure, between
1996 and 1999.  For comparison we also show the SUMER/SOHO solar
disk observations in the same range of the spectrum.  The UVCS
observations show a rough anti-correlation between the density
of the coronal structure at the observed heliographic height and
the line widths.

(The first UVCS results are presented by Kohl et al. 1997,
Solar Physics, 175, 613; the solar maximum equatorial coronal hole
observations are presented by Miralles et al. 2001, Astrophys. J.,
549, L257; the SUMER disk profiles are presented by Warren et al.
1997, Astrophys. J., 484, L91)