31 



drawn is the type most commonly employed for purposes of illustra- 

 tion. A dynamic section, Figure 12, formed by stations 201 to 206, 

 International Ice Patrol, 1922, is shown on page 30. 



VELOCITY— HOW DETERMINED 



We may now return to a consideration of e,quation (f ) , page 24 , in order 

 to find the velocity of the current between stations 206 and 205, by 

 substituting at the same time for dg, and d\y the values as found at the 

 six levels of observation of the two foregoing stations. Since the 

 velocity is the term desired, equation (f), page 24, may be written 

 in the following form: 



(^a -4)10- 



^° ^' 2cosm0„,XlO^ ^^> 



where </)ni = 41° — 10', the mean latitude of stations 206 and 205. The 

 value of 10^. 2co sin 0, by Table VI, page 32, is found to be equal to 9.60. 

 The multiple 10^ is introduced simply to bring the velocity values into 

 centimeter-gram-second terms. L, which is the distance between 

 stations, is equal to 32 miles, or 59 kilometers. (See Table VII, p. 33.) 



If we treat the values of d^^ — db as whole numbers and divide them 

 by the value of 2co sin 4),nL 10^ the latter of which is found equal to 

 569.28, we obtain the following: 



If it is assumed that Ci is equal to zero at a depth of 750 decibars 

 (meters), then the following velocities are furnished at the various 

 levels of observation, from the surface downwards. (If it is desired to 

 express velocities in terms of knots per hour, 10 cm. /sec. is equal 

 approximately to 0.2 knots per hour.) 



