The Botany of Iceland - 01.12.1914, Page 83

PHYSICAL GEOGRAPHY
267
The climate of Iceland, owing to oceanic currents, is much
milder than could be expected from the position of the island. As
is well-known the temperature of the air varies greatly at the same
latitude on the eastern and western sides of the North Atlantic.
Stykkisholm in Iceland lies ahout 65° N. lat. as also Brönö in Nor-
way and Angmagsalik on the east coast of Greenland, but the tem-
perature varies greatly in these three places as shown in the fol-
lowing table: —1
February July Average for year
Brönö................... — 1.4° C. 12.8° C. 5.2° C.
Stykkisholm............. — 2.7° C. 9.7° C. 2.8° C.
Angmagsalik............. —10.8° C. 5.4° C. —2.6° C.
The above table shows, among other things, tlie great influence
exerted by tlie cold, ice-carrying current in Denmark Strait. On the
whole, oceanic currents have a great effect upon the climate of Ice-
land. The west coast has its temperature raised by the Gulf Stream.
One branch of tliis passes Cape Nord and continues its course along
the nortli coast where it becomes cooled, but has still a compara-
tively high temperature which is dislinctly felt at Grímsey. Another
branch of the Gulf Stream cornes frorn the south up towards the
south and east coasts where it meels the cold Polar current which
conies down along the east coast of Greenland and at Iceland di-
vides into two branches. Of these branches the one broad branch
turns down through Denmark Strait, while the other flows down
towards Langanes, and thence southwards along the east coast of
lceland to South Iceland where it passes fietween the coast and the
warm current outside. The conditions connected with these currents
exert a great influence upon the temperature of tlie ocean olf dif-
ferent parts of the coast and thus upon the flora and íauna of the
ocean, whicli dilfer greatly according to whether tliey are under the
influence of cold or warm water. Thus, the algal vegetation along
the north-eastern coast of Iceland has a different character — is
more Polar — than towards the south-west; this applies also to
the fish fauna, and the deep-wrater, spot-bound fauna, as well as
to the plankton.
The temperature of tlie surface-water of the ocean varies there-
fore in no slight degx-ee off the different parts of the coast. During
winter the temperature of the ocean-water ofT the east coast, wliere
the influence of the Polar current is greatest, is on an average 0.8°
1 Julius Hann: Handbuch der Klimatologie. Stuttgart, 1908, I, p. 181.
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