Fróðskaparrit - 01.01.2002, Blaðsíða 110

108
ARCTIC MOUNTAIN METEOROLOGY AT THE SORNFELLl MOUNTAIN
IN YEAR 2000 IN THE FAROE ISLANDS
tain peak in the Faroe Islands, Slættaratin-
dur at 882 m asl., the air temperature of the
warmest month should be in average 5.5°C,
calculated from the Sornfelli air tempera-
ture data for the year 2000. Therefore low
arctic conditions today dominate from the
highest mountain peaks and down to
around 216 m asl. in the islands. However,
a slight mean temperature decline of only
0.5°C in summer would bring high arctic
conditions to the very peaks of the Faroese
mountains.
Between the temperate zone, where trees
can grow economically profitably and the
arctic climatic zone, the narrow subarctic
boundary zone exists, in which the air tem-
perature of the warmest month is just above
10°C, and low and dispersed woods can oc-
cur. The lower part of the Faroese land-
scape today has almost no woods, and in
Torshavn, at 54 m asl., the mean 30 year air
temperature of the warmest month is
10.4°C (Table 1), while at Sund, at 3.5 m
asl., in an inner fjord location (Fig. 2), the
air temperature of the warmest month ip
2000 was 11,5°C. Therefore the main part
of the lowermost 216 m of the Faroese
landscape seems to belong to the subarctic
zone. Heide-Jørgensen and Johnsen (1997)
also use the subarctic type, when character-
ising the Faroese climate as being subarc-
tic-temperate.
The complete climatological dominance
of low arctic and subarctic climatic condi-
tions at the Faroe Islands does not fít many
traditional maps of the southern boundary
of the northern hemisphere low arctic zone.
This border is often placed not far north of
the Faroe Islands, locating the Faroes in the
temperate climate zone. Such mapping,
however, often refers to conditions at sea
level. In the Faroes the zone up to 100 m
asl. comprises less than 10 % , due to the
topography (Fig. 1). Cold climatic condi-
tions similar to the Arctic in mountains out-
side the polar climatic zone are referred to
as alpine climates. Therefore the Faroese
low arctic zone could be termed alpine ac-
cording to this defmition, if conditions at
sea level were temperate. However, the
subarctic conditions at sea level and the
nearness to the arctic zone at sea level, as
e.g. just northwest of the Faroes in Iceland,
imply that the cold climate above 200 m
asl. in the Faroe Islands, should be includ-
ed in the low arctic climate zone of the
Northern Hemisphere.
The presented vertical distribution of cli-
mate zones at the Faroe Islands offers a
unique setting for monitoring meteorologi-
cal conditions in the southernmost part of
the northern hemisphere low arctic zone.
This is particularly important in the North-
east Atlantic area where variations in the
North Atlantic Drift could move the terres-
trial altitude of the low arctic zone. There-
fore it is important to obtain long-term me-
teorological data series from the Faroese
highlands, as it will be possible by operat-
ing the Sornfelli meteorological station for
a longer time period.