year drift and the calculated drift shows that the errors in calculating the individual monthly move- 

 ments were not of a systematic nature, i. e. , they were not in the method, but were chance errors 

 caused merely by the inaccuracy of the initial material and the approximate nature of the 

 calculations. 



The objectivity of the results obtained proves that the compilers of the mean monthly pres- 

 sure maps, which are based on calculations, had no idea that these maps would be used to compute 

 drifts. Furthermore, one might say that the isobars on the daily synoptic maps are drawn with 

 consideration of wind direction and thus the agreement between ice drift and direction of the isobar 

 is taken into account in advance, but this objection does not apply to the mean monthly and mean 

 ten-day pressure maps, because the isobars on such maps are drawn only with respect to the 

 average pressure, without consideration of wind. 



The complete agreement between the final points (plotted on the chart) of the calculated and 

 observed drift of the Sedov indicates that the coefficient assumed in the calculations was approxi- 

 mately 20 to 30 per cent too high. Actually, the drift of the oedou was not purely a wind drift and 

 the steady current carried the Sedov westward at a rate of approximately 25 miles per month. 

 This circumstance must be kept in mind in further considerations. 



An examination of figure 135 shows that the computed drifts of the station "North Pole" 

 (dashed line) and of the icebreaker Lenin depart considerably from the observed drifts. This does 

 not indicate that the established relationship between the distribution of pressure and the drift 

 elements is inaccurate, but rather, it confirms the relationship. Actually, all that has been said 

 applies to drift which is practically unaffected by the coastline, the bottom relief and powerful 

 steady currents. These factors were taken into account to a certain extent during the drift of the 

 Sedov , but not during the drifts of station "North Pole" and the icebreaker Lenin . 



Powerful steady currents, basically north to south, were observed in the drift region of the 

 station "North Pole". It is quite natural that under such circumstances the calculated drift would 

 not coincide with the actual drift, which consists of pure wind drift created by local winds and the 

 drift caused by steady currents. 



Figure 135 shows the drift of the station "North Pole" (dash dot) calculated by the method 

 outlined above, but with the introduction of a correction for the steady current (taken from table 

 105) in every monthly movement. Table 105 was compiled on the basis of the data of station 

 "North Pole". 



TABLE 105. ELEMENTS OF STEADY CURRENTS IN THE DRIFT REGION OF 

 STATION "NORTH POLE" 



Month 



(1937) 



May-June 



July 



August 



September 



October- November 



Mean Coordinates 



Latitude 



89° 00' 

 88 10 

 87 30 

 78 50 

 86 10 



Longitude 



20° W.L. 

 10° W.L. 



5° W.L. 



8° E.L. 



0° E.L. 



Current Elements 



Direction 



160 

 95 

 180 

 185 

 155 



Velocity In 

 Miles/Day 



1.4 

 2.2 

 1.2 

 5.0 

 1.2 



375 



