Fróðskaparrit - 01.01.2002, Side 104

102
ARCTIC MOUNTAIN METEOROLOGY AT THE SORNFELLI MOUNTAIN
IN YEAR 2000 IN THE FAROE ISLANDS
Air tempcrature Jan Feb Mar Apr May Jun Jul Auk Sep Oct Nov Dec Year
Mean -0.9 -2.0 -1.9 -2.2 2.6 3.0 6.1 6.5 5.4 3.2 0.6 -0.7 1.7
Min. -8.4 -7.7 -10.6 -9.1 -2.9 -3.2 0.7 2.3 0.8 -1.5 -5.4 -10.6 -10.6
Max. 8.6 4.8 4.2 6.1 12.3 9.1 14.6 10.9 12.5 7.3 5.6 5.7 14.6
Table 2. Mean monthly and annual air temperature (°C) at the Sornfelli meteorological station during tlie year
2000, calculated from the lialf hourly corrected temperature values.
sors were insufficiently ventilated. The
main use of the shielded sensor on the plat-
form is because of radiationál effects from
the ground heating the shielded fixed sen-
sor. This occurs when the ground is snow
covered or heated by the sun in summer.
Wind speed and direction
The wind speed data are scanned continu-
ously four times per second throughout the
10 minute platform exposure period. Three
parameters are calculated from these data:
A 10 min mean wind speed, a 32 sec gust
and a 2 sec gust. Wind direction is calculat-
ed as the average wind direction in 10 min-
utes. Some single spike values of extreme
wind speeds occurred on rather calm days.
These error readings most likely are caused
by rain or snow in the sound path. From 4
September 2000 wind and gust values
above 40 m/s have been filtered out of the
processed dataset.
The 10 min wind speed in the year 2000
(Fig. 7) had a mean value of 6.5 m/s. The
most windy periods occurred during the
late winter and mid autumn, with monthly
wind speeds up to 8.8 m/s, while the sum-
mer from May through August had mean
wind speeds generally less than 5 m/s (Fig.
Figure 6. Tlw corrected air
temperature for the year 2000from
tlie Sornfelli station based on data
from the three different temperature
sensors. For further details on tlie
construction of tlie curve see the
text. Mean annual air temperature
(MAAT) is shown.