does not dramatically deviate from 0.9 MK or so. It makes the plumes more or less isothermal, which is an assumption for the later calculations. Furthermore, above $\approx 120$ Mm the temperature plot is too noisy for a quantitative analysis. For the density, $\approx 150$ Mm to 170 Mm might be an approximate limit.

We projected a 3D plume onto LOS Doppler shift map as well to get a more precise outflow velocity along the plume by dividing the SUMER velocity with the cosine of the plume inclination angle to the LOS. However, we did not find any significant Doppler shift from SUMER observations, the maximum of the Doppler velocities is around 3 $\mathrm{km\,s}^{-1}$. If we take this number as a reference to estimate the outflow velocities along the plumes 0, 1 and 2, we found that they are quite small with a maximum of 10 $\mathrm{km\,s}^{-1}$. This speed is much smaller than the sound speed $c_s \approx 140\,\mathrm{km~s^{-1}}$ for a temperature of $\approx 0.9$ MK.

Similar to @Gabriel:etal:2003, we have made an estimate of the plume contribution to the fast solar wind. The proton flux density for the high-latitude fast solar wind observed during the solar minimum from Ulysses 