Jökull - 01.12.1991, Blaðsíða 11

Fig.10 : Mean summer temperature
1936-1985 (June-August), °C.
Mynd 10: Meðalhiti sumars (júní-
ágúst) 1936-1985, °C.
In northern Iceland the winter temperature is
above -1°C only at two coastal stations but is gener-
ally in the range - 1°C to -3°C in the lowland areas.
Winter temperature decreases towards the interior,
partly because of an increase in altitude and partly
because temperature in winter decreases with increas-
ing distance from the shore. This decrease may be
2°C/100km (Einarsson, 1984) with an exception in
the region Fljótsdalshérað in eastern Iceland as
already mentioned.
Mean summer temperature 1936-1985 (June-
August) is shown in Fig.10. Most lowland regions in
southern Iceland and the area around the capital
town have summer temperatures above 10°C. The
extensive lowlands in southwestern Iceland have
almost the same values, just above 10°C, from coast
to inland. A few very limited areas in other parts of
the country show values above 10°C, such as in
Borgarfjörður, Eyjafjörður and Fljótsdalshérað.
Otherwise lowland areas in western Iceland and
some areas in the northern and eastern part have val-
ues in the range 9°-10°C.
The lowest summer temperature of 7°-8°C, high-
lands excluded, is found along the north and east
coast of the country.
CORRELATION OF MONTHLY OR
ANNUAL TEMPERATURES BETWEEN
DIFFERENT WEATHER STATIONS
A correlation of monthly and annual temperatures
between different weather stations was calculated
using the 32 selected stations. This was done to test,
to what degree the temperature variations from year
to year are in phase in different parts of the country.
The stations were successively chosen as basic
stations and a correlation coefficient between tem-
perature values of the basic one and each of the
remaining 31 stations calculated for every month and
the year. The calculations were based on the years
each pair of stations had in common within the peri-
od 1901-1985.
A correlation coefficient near 1.0 between two sta-
tions would indicate that temperature variations
between years were almost exactly in phase. The
results indicate whether temperature variations at
one weather station are representative for the country
as a whole, a part of it or only a restricted area around
the location.
The correlation coefficients for annual temperature
prove to be in the interval 0.73-0.99. At most basic
stations they are >0.9 for a region extending from the
station and covering more than half of the country.
Only in 3% of all calculated coefficients are the values
JOKULL, No. 41, 1991
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