where c = speed of drift in km/hr 



X = distance in kilometers between isobars drawn at 

 intervals of 1 mb 



A = coefficient of proportionality. 



Subtracting in equation (1) the values: c = 1. 5 km/hr = 36 km/day = 1, 080 km/month, and 

 X = 15 km, we obtain the following value for the coefficient A : 



c (km/month) =16,200— (mb/km) (2) 



We recall that from analysis of the drift of the icebreaker Sedov , I obtained the following 

 equation: 



c (km/month) = 13,000— (mb/km) (3) 



Comparing equations (2) and (3) we see that their numerical coefficients are extremely close 

 and differ only within the limits of accuracy of the corresponding measurements. 



For a sea such as the White Sea, it is more convenient to use not equation (2) but the 

 following: 



AP 

 c (km/day) = 540— (mb/km) (4) 



If we assume that the speed of ice drift is the same along the whole width of the neck (approxi- 

 mately 46 km), we then find that the size of the ice area carried out of the neck of the White Sea per 

 day for the period under consideration is as follows: 



2 2 



q (km /day) = 46 km (5) 



AP 

 (km/day) = 25,000 — (mb/km)* (6) 



Equation (3), (4), and (5) refer to a case when the isobars run parallel to the axis of the neck 

 of the White Sea. But the isobars may run in various directions and may intersect the neck at var- 

 ious angles. For the general case we may write as an approximation 



Ap 

 c (km/day) = 540 cos (3 -r— (mb/km) (7) 



2 AP 



g(km /day)= 25,000 cos /? — (mb/km) (8) 



where j3 = angle between direction of isobar and axis of the White Sea. If the area of increased 

 atmospheric pressure is east of the neck of the white Sea, then angle p is considered positive, if 

 it is west of the neck, negative. 



*Editor's Note: Undoubtedly equations (5) and (6) should be 



q (Rm /day) = 460 (5) 



2 

 q (Rm /day) = 25, 000 / x (mb/Rm) (6) 



442 



