264 G - F - Me E wen. 



19. X== f = 31 



Substituting for (V ) its value in terms of the wind velocity from 

 equation (8) we have 



1= 8.U0067) v . 0,004 v 

 7^ 2 /sin* /sin* w 



where (x 1 ) is the average velocity in meters per second at which a 

 surface layer of thickness 5 meters leaves the coast and (V w ) is the 

 component of the wind velocity parallel to the coast in miles per hour. 

 Multiplying by the number of seconds in a month we have 



21 x 1Q48 V 



w . ^ v w- 



\ Sill V 



Substitute this value of (x) in equation (13) and the result is 



t=- 



which is a theoretical relation between (t) the reduction of the tem- 

 perature below the normal value, the wind velocity (V w ) parallel to the 

 coast, the normal temperature (t. 2 ), and the temperature (t ) of the 

 upwelling w r ater which causes the abnormally low actual temperature 

 (T). For any given place the latitude (#>) is constant, and observation 

 shows (ti), (x ), and (x. 2 ) to be practically constant. So the only va- 

 riables for a given locality are the wind velocity parallel to the coast 

 and the normal temperature. The wind velocity must be in miles per 

 hour and the distances (x ) and (x 2 ) in meters. 



VI. The application of the above theory to four selected regions, and 

 the comparison of the observed and computed values. 



Four stations on the coast were selected in which the factors 

 entering into the computation differed widely. For (t t ) the value 8 

 was used north of latitude 36 and 9 was used for the region south, 



but the value of (xi-j-yXsJ was chosen so as to give the best agree- 

 ment between the computed and observed values, but was assumed 

 constant for each statien. It seemed reasonable to use a value of (t ) 

 somewhat greater than the bottom temperature, as the water would 

 become w r armer as it rose and mixed with the layers above. The value 

 chosen is about the average of the mean annual surface temperature 



