Jökull - 01.12.1993, Blaðsíða 6

Figure 5. Mean monthly standard deviation of tem-
perature in 1925-1990 for Reykjavík, Thorshavn,
Nordöyan fyr, Björnöya, Jan Mayen, Angmagssalik
and Godthaab/Nuuk, in °C. — Árssveifla staðalfrá-
vika mánaðarmeðaltals hita (°C) árin 1925-1990 í
Reykjavík, Þórshöfn í Fœreyjum, Nordöyanfyr, Björn-
öya, JanMayen, Angmagssalik and Godthaab/Nuuk.
Figure 6. Numbers of years, for each of the 16 North-
Atlantic weather stations outside Iceland, when the
five warmest or coldest years in Iceland during 1901-
1990 occurred simultaneously at these stations.
— Fjöldi ára á 16 erlendu/nálœgu veðurstöðvunum
(sjá 1. mynd) þar semfimm hlýjustu eða köldustu ár
tímabilsins 1901-1990 á Islandi, mœldust einnig.
COMPARISON OF FIVE WARMEST AND
COLDEST YEARS 1901-1990 IN ICE-
LAND AND NEIGHB OURIN G WEATHER
STATIONS
For comparison of temperature conditions in Ice-
land and the neighbouring area we consider the spa-
tial coherence of extremes. Einarsson (1991) showed
a table of the 5 highest and lowest annual tempera-
tures during the period 1901-1990, for the 7 Icelandic
weather stations considered here. The question arises,
how many of the 5 warmest or coldest years in Iceland
during this period are also extreme in that respect at
some of the 16 eastern North-Atlantic weather stations
which are presented in this paper? The answer was
approached as follows: First, the 5 warmest and cold-
est years from the 7 weather stations in Iceland were
identified as:
a) the warmest years (10 years): 1928, 1933, 1939,
1941,1945, 1946, 1953, 1960,1964, 1972
b) the coldest years (14 years): 1902, 1903, 1906,
1907, 1914, 1917, 1918, 1919, 1921, 1968, 1969,
1979, 1981, 1983
This is altogether 24 years, and the question is,
whether 5 (or more) of the warmest or the coldest
years in Iceland were also such extreme years at the
16 other N-Atlantic stations. As an example the year
1939isone ofthe5 warmestyearsat6outof7 stations.
Figure 6 shows the numbers of years for each of
the 16 North-Atlantic weather stations, when some
of the 5 warmest or coldest years during 1901-1990
were also such extremes in Iceland. The number of
the extreme years for the 16 stations was 95, of which
the coldest years were 61 but the warmest years 34.
Some 42-54% (10/24 = 41.7%, 13/24 = 54.2%) of the
warmest/coldest years in Iceland are found to be ex-
treme in that respect within a rather large region around
Iceland (Figure 6). This region includes the Faeros Is-
lands, extends more than half way to W-Norway and
Jan Mayen, covers the Greenland Sea and a part of
4 JÖKULL, No. 43, 1993