As we see, according to Nansen the true wind factor is somewhat higher. I have already 

 mentioned that I do not know at what height above the ice the wind observations were made on the 

 Fram . It is quite natural that on the Sedou, where the wind measurements were made at a 

 height of 12. 5 m, i. e. , at a height probably greater than the height at which the observations were 

 made on the Fram. , the wind speed would be greater and this would be reflected in the compara- 

 tively smaller wind factor. 



Thus, rounding off and summing the data obtained by Nansen from his analysis of 76 drift 

 segments of the Fram and my analysis of 378 segments of the Sedo v drift, I find that in the Arctic 

 Basin far from the coastline and over great ocean depths the average angle of drift is 30° to the 

 right of the effective wind and that the drift velocity is 0. 02 of the wind speed causing the drift. * 



In table 102, one is struck by the small true drift angle obtained for February when the 

 Sedou drifted from 85° 36' north to 86° 20' north with prevailing southerly winds. One gets the 

 impression that during this time there was some obstacle to the north of the Sedo u drift, ob- 

 structing its northward course. This obstacle evidently consisted of great masses of pack ice 

 similar to the one on which station "North Pole" was established. However, this question also 

 requires further analysis. 



In conclusion one should note the following. It has already been pointed out that Nansen 

 attributed the rightward deflection to the deflecting force of the earth's rotation. However, Nansen 

 noted that the surface layers of water, deflected by the Coriolis force to the right in the northern 

 hemisphere, causes a current in the subsurface layers which is deflected even farther to the right. 

 Ekman's theory of wind currents, based on Nansen's findings, indicates that if one ignores the 

 inclination of the sea level, the angle of deflection of a pure wind surface current is not a function 

 of geographic latitude and is always 45°. At the same time, Ekman also developed a theoretical 

 angle between wind and ice drift, namely; 



tan ff = 1 + 2 1 6 ^ 



V (x) sin (p 



where i is the ice thickness, 6j the density of the ice, fi the viscosity coefficient and 6^, the 

 density of the water. 



If we substitute in this formula sine (p = 1, (5jy = 1, w = 0. 0000758, /x = 200, 6j =0.9 and 

 i = 300 cm, we get 



tan a = 1.162 



*Libin informs me that the average true drift angle was 31° and the average true wind factor 

 0.017 in the region of operations of the N-169 expedition (80° north 183° east). 



365 



