Jökull - 01.12.1993, Page 7

Figure 7. 10-year over-
lapping means of annual
temperature in the period
1901-1990 in Vestmanna-
eyjar, Thorshavn, Bergen,
Nordöyan fyr, Bodö, Tromsö
and Vardö. — 10 ára rað-
meðaltöl árshita 1901-1990
í Vestmannaeyjum, Þórshöfn
í Færeyjum, Bergen, Nord-
öyan fyr, Bodö, Tromsö, og
Vardö.
the coasts of the southern part of Greenland. Other
more distant regions, such as N-Greenland, the coast
of W-Norway and the northerly region of Norwegian
Sea, do not relate closely to the Icelandic extremes.
The thermal conditions for Iceland, derived from
annual temperatures (Figure 6) could be interpreted as
created by dominating air masses moving from west
or southwest but other types of air masses are certainly
involved.
possible to estimate how the numbers of extreme years
would have increased if the period of observation had
reached to the present date.
COMPARISON OF 10-YEAR OVERLAP-
PING ANNUAL MEAN TEMPERATURE,
1901-1990, BETWEEN ICELAND AND
NEIGHBOURING REGIONS
Of the coldest years in Iceland, used for this com-
parison, 9 were found during the period 1902-1921. In
Jan Mayen, however, observations started in the year
1922, and 1925 at Scoresbysund/Kap Tobin. There-
fore observations in Iceland could not be compared
with these two stations. However, the number of ex-
treme years in Jan Mayen during the century would
presumably only have increased by a few years, if
data were available for the two first decades of the
century. This assumption is supported by the fact that
in Angmagssalik, which has observations from the
period 1901-1990, only 5 extreme years, coldest or
warmest, are found during the period 1901-1921.
At the west coast of Greenland, the 4-8 warmest or
coldest years are somewhat fewer than in Iceland. It
should however be pointed out that the weather station
Ivigtut was in operation only until 1960 and it is not
Einarsson (1991) described the temperature varia-
tions in Iceland during this century and divided annual
temperatures in Iceland into cold or warm periods as
follows:
1901-1925
1926-1946
1947-1952
1953-1964
1965-1971
1972-1990
cold period
warm period
cold period
warm period
cold period
cold period
It is still questionable whether the period 1947-
1952 should be considered as cold, as it is only dis-
tinguished in some parts of Iceland and only in two of
the four seasons. Further, the cold period 1965-1971
is most pronounced in northern and eastern Iceland,
where sea ice or at least cold ocean currents appeared
frequently.
JÖKULL, No. 43, 1993 5