Jökull - 01.07.2003, Blaðsíða 38

Achim A. Baylich
Figure 2. Mean monthly wind velocities at the Dalatangi meteorological station ( 10 km east of Austdalur)
and the Latnjajaure Field Station (Latnjavagge, northern Swedish Lapland). – Mánaðarmeðaltöl vindhraða á
Dalatanga og í Latnajaure, Lapplandi.
veloped below rock walls and rock ledges there are
Pleistocene moraines in the catchments. The regolith
thicknesses are generally small (Beylich 1999a). The
North European flora, apart from dwarf shrubs, is
formed by meadows and cryptogams (mosses and
lichen) (Glawion 1985). With increasing altitude, the
gaps in the vegetation cover increase, so that above
500 to 600 m a.s.l. there is hardly any closed vegeta-
tion. Larger areas, particularly convex slope surfaces
exposed to the wind, are free of vegetation or affected
by turf exfoliation (“Rasenabschälung”) (Troll 1973;
Glawion 1985). There is probably no permafrost in
the area. Active denudative slope processes are frost
shattering, rockfalls, boulder falls, ground avalanches,
debris slides and flows, creep processes, chemical de-
nudation, nivation, aquatic slope denudation (slope
and rill wash), and deflation. The steep main channels
are predominantly resistance-limited bedrock chan-
nels with numerous knickpoints, displaying high flow
velocities and highly turbulent discharges. Dissolved
salts, suspended sediments and debris are transported
in the main channels. Typical are high temporal vari-
ations of discharge, with high runoffs during intense
thaws and heavy rainfalls (Beylich 1999a).
MORPHOCLIMATIC INVESTIGATIONS
Geomorphologically Relevant Aspects of the Wind
Regimes
Seasonal wind variations at Dalatangi and Latnjajaure
are shown in Figures 2 and 3. The highest wind speeds
occur at both stations during the autumn and winter
months. The Dalatangi values are significantly higher
than at Latnjajaure.
High wind speeds particularly occurring with au-
tumn and winter snow storms generate a very irregular
snow distribution in both areas. In both environments
convex slope surfaces exposed to the wind are largely
36 JÖKULL No. 52, 2003