the formation and decay time of a plume. @Wang:1998 assumes a bright-point lifetime of around 12 hours, while for plumes he assumes lifetimes around one day. From the case study of June, we find that care is required when paring plumes with bright points. Spatial coincidence in a single image could easily be misleading.

For the data set in April, based on the results of 3D reconstruction and electron temperature, electron density and Doppler shift derived from the SUMER observations, we calculated the density scale height by assuming that a plume is in hydrostatic equilibrium. Using the reconstructed 3D direction of the plumes in space we could set an upper limit of 10 $\rm{km~s^{-1}}$ for the outflow speed along the plumes. The absence of a significant flow in plumes at heights less than 1.2 $R_{\odot}$ is in agreement with the conclusions of @Wilhelm:etal:2000 and @Raouafi:etal:2007. The temperatures derived from the density scale height were all in excess of 1 MK, while SUMER derived electron temperatures were well below 1 MK from line ratios of Mg[ix]{}. The ratio of the temperature obtained from the scale height, $T_\lambda$, to the blue electron temperature from SUMER, $T_{\rm s}$, is $T_\lambda/T_{\rm s}\approx$ 1.62 to 