Ocean Temperatures along the West Const of North America. 263 



compared with the observed temperatures, which are given for the same 

 time interval. 



From equation (12) the following equation for calculating (t), the 

 difference between the normal temperature (t. 2 ) and the actual tem- 

 perature (T) was obtained: 



13. t, - T = t = 



where (x) is the length, normal to the coast that multiplied by the 

 cross section (y X 1) of the volume considered, gives the amount of 

 cold water intruding, and (x + x 2 ) is the distance from the coast out 

 to the point where the temperature is practically normal. Now if this 

 quantity (x), which depends upon the amount of water up welling in 

 one month, can be determined, then the temperature reduction (t) can 

 be calculated by substituting in equation (13) if the normal temperature 

 and that of the upwelling water are known. 



With the aid of Ekmans theory (x) can be computed as follows. 

 The flow normal to the coast due to the surface current between the 

 depths (z ) and (z 2 ) is 



/5 



= I 



^ 



14. s= I udz 



where (u) is the velocity normal to the coast. From Ekman's equation 

 this reduces to 



15. s = V e' az cos (45 az) dz 



where 



D 



Integrating between these limits and simplifying the result we have 



17. s == = (1 2' k7r cos kTr) = approximately, 1 ) (knr ) 



where a surface layer down to the depth (kD) is considered. 



Observations show that the temperature is practically uniform from 

 the surface down to the depth of about 5 meters, so the value of (y) 

 can be taken equal to 5 meters or 0.06 (D) where (D) is 75 meters. 

 Substituting this value of (k) in equation (17) gives 



18. g = 0,l86VoD = QQ418V D and 



V 2 7i 



J ) This approximation is true only for small values of (kTr), the error being 

 less than 3 / if (k n) is less than 0.5. 



