Jökull - 01.12.1969, Page 14

in the coldest period (1853—1892). On the
other hancl the number of icemonths and
temperature for each winter are not closely cor-
related. The winters were very cold in 11 of
the 25 iceyears, 5 were cold, 8 normal and 1
very warrn. The last one is the winter in 1932
with prevailing southwesterly winds, which
hindered the movement of the ice towards
south between Iceland and Greenland.
The temperatures of the spring in Fig. 2
show the same main features as in the winter,
even if the warm springs in the middle of the
19th century last longer than the mild winters.
The first extremely cold spring is the spring
in 1859, with mean temperature — 1.0° C.
From that time cold springs dominate the
picture until 1925. No clear connection was
found between ice ancl temperature of tlie
spring in Stykkishólmur.
The summers are coldest from 1858 to 1888,
but the mean temperature for this period lies
only 0.4° C below the general average. The
warmest summer period is 1925—1961, with the
mean temperature 9.2° C, but after 1950 there
is a cooling trencl and after 1961 all summers
except two are equal to or below the general
average, and these two exceptions are only 0.2—
0.3° C over the average.
In this connection it is important to bear
in mind the influence of the temperature dif-
ference between wall screen and free standing
hut. Usually the wall screen gives higher tem-
perature during summer, and the real tem-
perature dilference between the coldest and
warmest period is therefore doubtless greater
than the figures indicate.
The most outstanding feature in the autumn
series is the warm period 1931 — 1965. In this
period 50% of the autumns are warm or very
warm, one autumn is on the upper limit for
cold autumns, but no autumn is very cold.
During these 123 years the annual tempera-
ture varied from 0.9° C in 1859 and 1866 to
5.2° C in 1941. The rnean annual temperature
was 3.4° C. The lower limit for warm years is
3.9° C and the upper limit for cold years 2.8° C.
During the coldest winter period the mean
annual temperature was 2.8° C, but the warm-
est years are 1926—1965 with average tempera-
ture 4.2° C. The 3 last years in this series
1966—1968 liave annual temperature from 3.0°
to 3.2° C, and they are the first years under
the general average after 1925 with the except-
ion of 1943 and 1949 which were 0.1° C be-
low the average.
10
JÖKULL 19. ÁR