We study the hydrogen Lyman emission in various solar features - now
including Lyman-alpha observations free from geocoronal absorption - and
investigate statistically the imprint of flows and of the magnetic field on the
line profile and radiance distribution. As a new result, we found that in
Lyman-alpha rasters locations with higher opacity cluster in the cell interior,
while the network has a trend to flatter profiles. Even deeper self reversals
and larger peak distances were found in coronal hole spectra. We also compare
simultaneous Lyman-alpha and Lyman-beta profiles. There is an obvious
correspondence between asymmetry and redshift for both lines, but, most
surprisingly, the asymmetries of Lyman-alpha and Lyman-beta are opposite. We
conclude that in both cases downflows determine the line profile, in case of
Lyman-alpha by absorption and in the case of Ly-beta by emission. Our results
show that the magnetically structured atmosphere plays a dominating role in the
line formation and indicate the presence of a persisting downflow at both
footpoints of closed loops. We claim that this is the manifestation of a
fundamental mass transportation process, which Foukal back in 1978 introduced
as the 'coronal convection'.Comment: 8 pages, 5 figures, accepted for publication in Cent. Eur. Astrophys.
Bul