Jökull - 01.12.1993, Blaðsíða 11

Figure 12. Mean deviation of annual temperature in
1965-1971 and 1925-1990. Calculated with the stan-
dard deviation 1925-1990 as a unit. — Meðalfrávik
árshita 1965-1971frá 1925-1990. Staðalfrávikl925-
1990 eru notuð sem eining.
to Angmagssalik show the most negative deviation i.e.
-1-5. Further, most of the stations from Iceland to
Svalbard have deviations between -1.0 and -1.5.
It is interesting that both the coldest periods of
the century, i.e. 1901-1925 (Figure 10) and 1965-
1971 (Figure 12) show the most negative deviations
near and surrounding Iceland. The first one reaches
mostly from Iceland towards northwest, but the second
one north to Svalbard. The year 1968 is the coldest
°ne, both in Jan Mayen and Scoresbysund, but not in
Angmagssalik. In Björnöya, Isfjord radio and Hopen
the same year was very cold. In Iceland, for instance in
Grímsey, the year 1968 was also very cold, but not the
coldest one during the century, and not a single cold
year, because 1967 and 1969 were almost equally cold.
Further, 1965-1971 was a cold period as already men-
tioned. The 5 coldest years of the century in Grímsey
were 1902,1907, 1917,1918 and 1979.
We can conclude that the weather stations dis-
cussed above, i.e. Jan Mayen, Scoresysund/Kap To-
bin and Angmagssalik, had very similar temperature
characteristics as Grímsey. That is also valid for Teig-
arhorn.
IV. Ivigtut 1901-1960, Godthaab/Nuuk 1901-1990,
Jakobshavn 1901-1990, Upernavik 1901-1980
Figure 13 shows 10-year overlapping means of the
annual temperature for the weather stations at Green-
lands west coast for comparison with the Icelandic
stations, Reykjavík and Grímsey. The range between
the highest and lowest values are rather large at these
stations, 1.7°C for Ivigtut, 2.1°C in Godthaab/Nuuk,
2.9°C in Jakobshavn and 3.1°C in Upernavik. The
phase is similar at the four stations, but variations in-
crease towards north.
As in the other figures we have considered, a very
cold period is seen at these stations in the beginning of
the century. Then a warming started around year 1923
(or 1918/27 on the graph). Following a maximum
in 1927/36. After that the two southernmost stations
show small variations, but at the northernmost sta-
tions (Jakobshavn, Upernavik) a cooling continued to
1937/46. After that the temperature increased some-
what, but then became lower from 1960/69 with a
minimum in 1967/76. Then temperatures increased
by 1971/80. A cold period is seen 1966-1975, and
the year 1972 is especially cold. Later the cold years
were in 1983 and 1984. Angmagssalik has rather sim-
ilar variations as the stations in W-Greenland (Ivigtut,
Godthaab/Nuuk).
A comparison between weather stations at W-
Greenland and Icelandic stations show a somewhat
similar increase of temperature near 1920, and the di-
agrams of Ivigtut and Godthaab/Nuuk are partly simi-
lar to those of the Icelandic stations (Grímsey, Reykj-
avík). In the northernmost stations the temperature
increased more rapidly, which created a distinctive
maximum, only seen in Jakobshavn and Upernavik.
The cold period 1965-1971 is distinct in W-Greenland,
but developed gradually later than in Iceland.
The weather stations of the southwest coast of
W-Greenland (Ivigtut, Godthaab/Nuuk) show similar
temperature variations as the Icelandic weather sta-
JÖKULL, No. 43, 1993 9