SURFACE WATERS OF THE NORTH ATLANTIC OCEAN. 
113 
current through the Faeroe-Shetland Channel and between Faeroe and Iceland, and 
by the two branches of the Irminger current, one west of Iceland, the other west of 
Greenland. As it seems desirable that this northerly current should have a distinc¬ 
tive name, it might be well to call it the European stream, and its branches the 
Norwegian, Irminger, and Greenland streams respectively. 
The strength and volume of the European stream is liable to considerable variation, 
according to the form and position of the Atlantic anticyclone, which causes the 
amount of banked-up water and the proportions escaping northwmrd and southward 
to vary. It is also modified by the strength and direction of the surface drifts in its 
course. It is, however, always strongest in summer. 
4. The Norwegian stream is by far the largest branch of the European, and it 
traverses the Norwegian Sea and enters the Arctic Ocean. The warm wmter thus 
sent northward melts enormous quantities of ice, and the fresh water derived from 
the ice moves southward in autumn, chiefly in a wide surface current, between Iceland 
and Jan Mayen, which may entirely cover over parts of the Norwegian stream. Part 
of the surface water also comes soutliward through the Denmark Strait, but the 
amount is much smaller, probably chiefly because the melting of the ice is slower, and 
the channel is longer blocked. 
The Greenland branch of the European stream also causes melting of ice in llavis 
Strait, but the warm winds from the American continent and the large quantity of 
wmter received from the land are i^robably more eftective in increasing the volume of 
the La.brador current. 
5. The water from the melted ice is spread over the surface of the North Atlantic 
during late autumn and winter by the increasing drift circulation, and it is 
gradually absorbed by mixing with the underlying water. 
6. The circulation described is liable to extensive variations corresponding to varia¬ 
tions in the atmospheric circulation. 
The meteorology of the North Atlantic area during tlie period under discussion, 
and the reaction of the oceanic upon the atmospheric circulations, really form part of 
a separate investigation, and will be discussed in anotlier j^aper. Special interest 
attaches to the departures of the monthly temperatures from the mean and their 
relation to the ]U'essure anomalies. One or two important points, however, may be 
touched on. 
Quite recently, Pettersson and Meinardus (49) have shown that a relation exists 
between the mean barometric pressure over an oceanic area during the winter months, 
and the temperature of its surface voters; high temperatures tending to lower 
pressures, and low temperatures to higher pressures. This is jDrobably seen on its 
largest scale in the southern hemisphere, whiere the areas west of the land masses 
(50), supplied with cold water Ijy the Antarctic currents, coincide with the strongest 
developments of tlie southern high-pressure belt. 
It has been showm that the exiDansion north-eastward of the Atlantic anticyclone 
VOL. CXCVI.—A. O 
