OCEAN TEMPEBATURES 



397 



TABLE 12 

 Normal surface temperatures and temperature reductions in the San Diego region. 



From line 3, table 10 (p. 387). 



The agreement between the predicted monthly temperatures and 

 ' the observed averages is very satisfactory. Moreover, from the rela- 

 tion of the vertical velocity to depth deduced from hydrodynamical 

 principles, and shown by table 13, the velocity w at the 3 meter level, 

 would be .116^, where w is the velocity below the 40 meter level. 

 - That is, the value of w to be expected from that deduced from deep 

 water temperautres (p. 403) is .116 X ( 31) equals 3.6, which 

 agrees well with the value 3.0 deduced from the surface temperature. 



DEDUCTIONS KELATIVE TO OCEANIC CIRCULATION IN THE SAN DIEGO 

 REGION BASED ON EKMAN 's HYDRODYNAMICAL THEORY 



Zoppritz (1878) obtained some theoretical results relative to oceanic 

 circulation, from the general equations of motion of a viscous fluid, 

 and some of his conclusions have been widely used by oceanographers 

 and geographers ; but a critical examination made in the light of later 

 observations showed that his conclusions do not apply to conditions 

 found in nature. These erroneous conclusions are due to his failure 

 to take into account the deflecting force of the earth's rotation and 

 to his use of the laboratory value of the coefficient of viscosity. The 

 importance of the effect of the earth's rotation on currents in the air 

 and ocean was pointed out long ago by Hadley, Coriolis, and Ferrel ; 

 but with the exception of free currents, that is, currents moving by 

 their own inertia, the deflecting force due to the earth's rotation was 

 thought to be so small that it could be neglected until Bjerknes 

 (1901) first made clear the importance of this deflecting force in the 

 case of forced currents. 



