388 



MISCELLANEOUS STUDIES 



TABLE 11 



Theoretical temperature reduction at the depth of 40 meters corresponding to a 

 series of values of the vertical velocity ;,. 



From plates 24 and 36 (McEwen, 1916), and from an examination 

 of the temperature data (Michael and McEwen, 1915, 1916) it appears 

 that the temperature reduction at the 40 meter level, inshore averages 

 from 2 to 3 more than that ten miles offshore. Also surface tem- 

 peratures as much as 9 below the normal have at times been found 

 close inshore in July or August, when the normal temperature is 

 about 23, while the reduction of the surface temperature ten miles 

 offshore does not at any time exceed 3?5 (table 12). If, corresponding 

 to a temperature reduction of 1?7 ten miles offshore, the inshore 

 reduction is 1?7 plus 2?5 equals 4?2, the corresponding velocity of 

 upwelling inshore would, from table 11, be about twice as great as 

 that ten miles offshore. 



DEDUCTION OF THE CHANGE IN SURFACE TEMPERATURES DUE TO A 



VERTICAL FLOW OF WATER NEAR THE SURFACE 



Statement of assumptions and mathematical formulation of the 



problem, and solution for the case in ivhich the 



flow is constant. 



The temperature reduction at the 40 meter level due to upwelling 

 applies also to the surface water, but owing to the upwelling in this 

 upper level the surface temperature will be still more reduced. The 

 time rate of change of temperature in the case of no resultant flow 

 given by the differential equation (10) on page 342 plus the term 



ti' will be the modified rate due to the vertical flow w as on 

 6y 



page 354. Hence the new differential equation corresponding to a 

 vertical flow near the surface is 



dT 



where k = k^ 



a t + a z x) cos a* -f a 3 x + 1] 



w 



oy 



(139) 



