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$\begin{figure} \par\includegraphics[width=8.35cm,clip]{gfx/2159fig1a.eps}\par\includegraphics[width=8.35cm,clip]{gfx/2159fig1b.eps}\end{figure}$ Figure 1: EIT/SOHO images in the Fe IX/X (171 Å) line. The areas scanned by SUMER are outlined by white contours. Upper panel: equatorial region observed on March 7, 1997. Lower panel: polar region observed on September 21, 1996. The area outlined by the dashed contour shows the observations used for the correction of data set 2.
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In the text

$\begin{figure} \par\includegraphics[width=17cm,clip]{gfx/2159fig2.eps}\end{figure}$ Figure 2: Data set 1. The Coronal hole is outlined by a thick solid line on the filtered continuum image, the Dopplergram and the Ne VIII intensity image. Upper left: continuum intensity image taken with SUMER/SOHO on logarithmic scale. Middle: filtered version of the left image with contour plot $\log({I/\langle I \rangle}) = 0.25$ in thin black solid line. Right: reconstructed magnetogram from data taken with MDI/SOHO. The thin contour plots of the Ne VIII intensity image and the filtered continuum image are overplotted on this image. Lower left: Dopplergram of the Ne VIII (770 Å) line observed on March 7, 1997. Middle: the line shift across the network from cell centre to cell centre, i.e. along the long edges of the box, is shown in the upper panel for the box "Ex.''. Right: Ne VIII line intensity image with contour plots of $\log({I/\langle I \rangle}) = -0.40$ in thin white solid line.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{gfx/2159fig3.eps}\end{figure}$ Figure 3: Data set 2. The polar coronal hole is outlined by a solid line. Values outside the disc are set to zero. Upper: filtered continuum intensity image on logarithmic scale computed from the continuum intensity taken with SUMER/SOHO. Middle: Ne VIII (770 Å) line intensity taken with SUMER/SOHO. Lower: Dopplergram of the Ne VIII (770 Å) line observed on September 21, 1996 corrected for the centre-to-limb variation.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{gfx/2159fig4.eps}\end{figure}$ Figure 4: Solid lines refer to the equatorial region, while dotted lines refer to the polar region. Each region is separated in two parts: quiet Sun and coronal hole. The vertical dashed lines give the median value of the corresponding histogram. Upper panels: histogram of filtered continuum image. Lower panels: histogram of the Ne VIII line intensity image.
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In the text

$\begin{figure} \par\includegraphics[width=17cm,clip]{gfx/2159fig5.eps}\end{figure}$ Figure 5: Dispersion plots showing the relation between filtered continuum intensity and Ne VIII Doppler shift, in solid lines. The dispersion plots are fitted by linear fits in long dashed lines, where a is slope of the fit. The left column shows quiet Sun data, the right column coronal hole data. In the first row data from the equatorial region were used, the second row describes the data from the polar region. The standard deviation of the median value is represented by the shaded areas. The vertical long-dashed lines show the position in the dispersion plot where the maximum blue-shift is reached.
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In the text

$\begin{figure} \par\includegraphics[width=17cm,clip]{gfx/2159fig6.eps}\end{figure}$ Figure 6: Same as Fig. 5, but relating the Ne VIII line intensity to line shift.
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In the text

$\begin{figure} \par\includegraphics[width=17cm,clip]{gfx/2159fig7.eps}\end{figure}$ Figure 7: Filtered continuum intensity images on logarithmic scale with white patches showing regions with the highest blue-shifts. Left: polar region with "highest blue-shifts'' defined as those larger than 5 km s^-1 for the quiet Sun, and larger than 8 km s^-1 for the coronal hole. Right: equatorial region with blue-shifts larger than 9 km s^-1 for the quiet Sun, and larger than 15 km s^-1 for the coronal hole. The coronal hole is outlined with a black solid line. The highest blue-shifts clearly cluster along the network boundaries for the equatorial region; this result is not as obvious for the polar region.
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In the text

$\begin{figure} \par\includegraphics[width=8.35cm,clip]{gfx/2159fig1a.eps}\par\includegraphics[width=8.35cm,clip]{gfx/2159fig1b.eps}\end{figure}$	Figure 1: EIT/SOHO images in the Fe IX/X (171 Å) line. The areas scanned by SUMER are outlined by white contours. Upper panel: equatorial region observed on March 7, 1997. Lower panel: polar region observed on September 21, 1996. The area outlined by the dashed contour shows the observations used for the correction of data set 2.
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$\begin{figure} \par\includegraphics[width=8cm,clip]{gfx/2159fig4.eps}\end{figure}$	Figure 4: Solid lines refer to the equatorial region, while dotted lines refer to the polar region. Each region is separated in two parts: quiet Sun and coronal hole. The vertical dashed lines give the median value of the corresponding histogram. Upper panels: histogram of filtered continuum image. Lower panels: histogram of the Ne VIII line intensity image.
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$\begin{figure} \par\includegraphics[width=17cm,clip]{gfx/2159fig6.eps}\end{figure}$	Figure 6: Same as Fig. 5, but relating the Ne VIII line intensity to line shift.
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