DEC 1 6 1930 
LISRARY 
NEW YORE 
‘OTANICAL 
GARDEN 
I. THE ICELANDIC CLIMATE. 
HE.climate of Iceland is, according to Thoroddsen 1914 p. 265 f., 
determined not only by the geographical situation of the island 
and the prevalent winds of the North Atlantic, but also to a great 
extent dependent on the current-conditions of the surrounding seas. 
The south and west coasts of Iceland are washed by the warm 
Gulf Stream, while on the north and east coasts we have the cold 
polar current. The waters of the two currents meet in the sea out- 
side south-east of Iceland itself, on a line running from Vatnajökull 
to the Færoes and to the north-west off Cape Horn. It is as well 
to note at once that in the highland tracts of Iceland between these 
two points, we find a series of jökulls in decreasing volume from 
Vatnajökull to the jökulls of Vestfirdir. 
The current conditions may be more precisely described as 
follows: The Gulf Stream washes the shores of Iceland all along 
the south and south-west coasts of the island, gradually gathering 
to a stream which follows the coast towards the west and further 
towards the north. Off Cape Horn, this branch of the Gulf Stream, 
known as the Irminger Current, encounters the Polar Current coming 
from the Polar Sea. A branch of the Irminger Current again is 
forced outward from the- coast by this Polar Current, and another 
branch, rounding Cape Horn, follows the northern coasts of the 
island to the eastward, cooling as it goes, and finally disappearing 
under the water masses of the Polar Current itself. At Grimsey, it 
is still of great importance, but farther east, it vanishes altogether, 
and the shores of East Iceland are thus washed solely by the polar 
water. The situation, then, is as follows: the south and west coasts, 
i. e. the coast south of the “jökullsline’” is washed exclusively by water 
from the Gulf Stream. The north and east coasts are washed by 
polar water; the eastern by this alone, the northern by this and 
Gulf Stream water as well. 
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