Jökull - 01.12.1991, Page 15

°c
18 -
16
14
12
10
8
10 12 14 16 18
Fig.15 : Comparison of the maximum
temperatures in summer for six
weather types between four pairs of
weather stations. Correlation coeffi-
cients (r) of the temperature of July,
and in two cases the regression lines
between the same stations follow.
Mynd 15: Samanburður hámarkshita
að sumarlagi í sexflokkum veðurlags
milli nokkurra veðurstöðva.
Fylgnistuðlar (r) júlíhita milli sömu
stöðva, og í tveim tilvikumfylgnilínur,
fylgja með.
southwestern part, at least when coastal stations are
excluded. This was already seen in Fig.6 describing
the distribution of the standard deviation of the July
temperature.
It must be pointed out that examples of this kind
would give a rather poor result when comparing two
stations, both with a small variation of summer tem-
peratures.
TEMPERATURE VARIATIONS 1901-1990
Two previously published papers on temperature
variations in Iceland should be mentioned. The paper
“Temperature variations in Iceland” (Eyþórsson,
1949) was based on measurements at Stykkishólmur,
Grímsey, Teigarhom, Vestmannaeyjar and Reykjavík
from start of observations and several stations in
addition since 1901. It seems that formulae were used
without further corrections. The temperature varia-
tions were mainly described by using 10-year and 30-
year overlapping means up to the year 1948. Two
decades later a paper on temperature variations in
Iceland 1846-1968 was published (Sigfúsdóttir,
1969), based on conformed temperature measure-
ments at Stykkishólmur.
In the following the main characteristics of tem-
perature variations in Iceland during the present cen-
tury will be described, based on partly revised
monthly and annual mean temperatures of the select-
ed weather stations.
It has already been mentioned that the variations
of the annual temperature in Iceland from year to
year tend to be in phase in different parts of the coun-
try, although the amplitudes may be different (see
Fig.4). Fig.16, showing the annual temperature from
year to year at Reykjavik and Akureyri for the period
1901-1990, confirms this. The variations are gener-
ally going in the same direction at both stations but
are larger at Akureyri. The difference is particularily
large in some cold periods such as 1914-1919 and
1965-1971. It can be concluded from this figure that
temperature variations in Iceland have been consid-
JÖKULL,No. 41, 1991 13