fact that they carry a huge quantity of heat from solar radiation and advective heat of the atmos- 

 phere during the summer season. 



The importance of the cold currents, particularly such as the East Greenland and Chuckchee 

 currents, lies not only in the fact that they carry arctic ice into the warmer regions, but also in 

 the fact that their surface layers, at the start of freezing, are comparatively fresh due to the 

 thawing of ice, their temperature is close to the freezing point, and in addition, they always carry 

 a greater or smaller number of ice fragments — the cores of future ice formation. 



The outline of the coasts and the deflecting force of the earth's rotation have a great influence 

 on the direction of the permanent currents. Thus, in certain seas which are bordered by fairly 

 large archipelagos and which are connected with other basins by fairly wide straits, very curious 

 circulations are produced. I have determined these for the northern hemisphere using the follow- 

 ing simple rules: 



1. In the central part of the basin a cyclonic (counter-clockwise) movement is produced. 

 The light water (in vertical section) is driven out in wedge fashion, with the wide side of the wedge 

 towards the shore, while the heavy deep water is raised up in the center of the basin with the dome- 

 shaped swelling towards the top. In certain cases (with thin surface layer and great speed of cur- 

 rent), the deep water may even come up to the surface. 



2. Around large archipelagos and islands, currents are created which round the archipela- 

 gos in a clockwise direction (anticyclonic) . 



3 . If you look down the length of sufficiently wide strait and stretch your right hand forward 

 and left hand back, the direction of your outstretched hands will show the directions of currents 

 along the corresponding shores. 



The greatest peculiarities are found in currents created by temporary winds when the water 

 cannot obtain the equilibrium determined by the coasts and the water masses when not influenced 

 by the given wind. Theory and observations mark the following factors in such currents: 



1. In the northern hemisphere the surface wind-caused current deviates towards the right at 

 a considerable angle. (According to Ekman's theory, at a distance from the coast the angle of de- 

 viation is equal to 45° for all speeds of wind and currents and for all geographic latitudes). Near 

 the coasts, however, the current may deviate toward the left. 



2. The sub-surface currents deviate from the surface current in the same direction as the 

 surface current deviates from the wind and the speed of current decreases with depth according to 

 the logarithmic law. 



3. The speed of the surface current is approximately one fiftieth (1/50) the speed of wind. 



Currents similar to wind-caused currents are created under ice fields which are drifting 

 under the force of shortlived winds . 



It must be emphasized that the aforementioned peculiarities are characteristic only of wind- 

 caused currents, i.e. , those created by temporary winds where the sea level is not yet Inclined 

 under influence of deflective force of the earth's rotation. In currents which are caused by per- 

 manent or prevailing winds, as for example the North Atlantic Drift and the East Greenland current 



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