406 MISCELLANEOUS STUDIES 



Figure 17 represents the component of the hypothetical circulation 

 in a plane perpendicular to the coast corresponding to a uniform \\ind 

 over the whole region, in which the bottom bends sharply upward at 

 the coast, but gives some idea of the actual circulation. In examining 

 the figure it must be noted that the vertical is very much greater than 

 the horizontal scale. In fact, if the horizontal scale were the same 

 as the vertical one actually used the diagram would be about one and 

 one-half miles in length. 



DEDUCTION OF THE UPWELLING VELOCITY OFF SAN DIEGO FROM THE 

 OBSERVED RELATION OF SALINITY TO DEPTH 



If the rates of molecular diffusion of salts and conduction of heat 

 are relatively very small as compared with the rate of transfer due to 

 the alternating circulation (p. 368), the differential equation 





W (200) 



6t dy 2 dy 



(equation 80, p. 368) applies in general where the constant p- is a 

 measure of the rate of transfer, and the dependent variable is the salt 

 concentration or temperature. An application to temperature data 

 has already been made, and we have only to replace by the salinity 

 8 in the temperature equation and its solution already worked out 

 (pp. 375-378) in order to obtain the corresponding formulae for 

 salinity. However, the salinity data are too incomplete to furnish 

 reliable estimates of averages for each month, and it seemed best to 

 use the data taken in the same region (Section 40 4 ) for each of the 

 three months, August, 1912. February, 1913, and April, 1913, which 

 correspond to an interval of less than one year. These data are 

 presented in table 15. 



