58 EIGHTH PACIFIC SCIENCE CONGRESS 



lags between the temperature cycles of coastal and offshore waters (OM, 

 3, 1951). 



In 1951 Hidaka published the result of a computation of the gen- 

 eral circulation of the Pacific Ocean. This is a modification of Munk's 

 theory, the only differences being the use of spherical coordinates in- 

 stead of Munk's rectangular, and the assumption of two types of wind 

 system— zonal and anticyclonic. He obtained practically the same re- 

 sult as Munk's, except a better agreement than Munk's of total mass 

 transport with the actual value 65 million tons per second obtained by 

 Sverdrup from Japanese observations. It must, however, be borne in 

 mind that the exact value of total mass transport is very hard to deter- 

 mine, the recent observations by Japanese giving about 20-40 million 

 tons per second (J. Masuzawa, KH, 2, 1951) according to the seasons of 

 the year. This value is far smaller than that of Sverdrup and agrees 

 with Munk's theoretical result pretty well. 



In 1952 Masamori Miyazaki published a new theory of the wind- 

 driven circulation and could explain the counter-current observed be- 

 tween the Gulf Stream and the American continent by assuming a zone 

 of smaller value of the coefficient of lateral eddy viscosity close to the 

 coast. This counter-current has been observed from a long time ago 

 and many authors have failed to explain except Rossby, who could 

 solve it by taking into account the effect of inertia terms (OM, 4, 1952). 



Yasukazu Saito made a very elaborate mathematical analysis on the 

 theory of ocean currents driven by winds in an isotropic ocean taking 

 into account the mixing in all directions. He used the velocity itself 

 for solving the problems (KS, 28, 1950, 25-61; TUFJ, 38, 1951, 87-179). 



Recently Hidaka solved a three-dimensional theory of ocean cur- 

 rents, thus making it possible to discuss the vertical structure of wind- 

 driven current. The most outstanding conclusion is that the motion 

 of water is much more intense than is expected in layers far below than 

 the depth of frictional influence defined by Ekman (in press). 



As to the fluctuation of oceanic circulation caused by the wind 

 fluctuation, Ichiye made an attempt to determine the curl of the wind 

 stress in each 5° square over the Pacific from actual observations. Fur- 

 ther he could determine the annual variation of the horizontal mixing 

 coefficient on the basis of the spectral theory of turbulence, and dis- 

 cussed the variation of circulation equalitatively (OM, 4, 1952). 



In 1952 K. Kajiura used the idea of Sverdrup and Reid in comput- 

 ing the current velocities in the upper layers of the eastern portion of 

 the equatorial Pacific on the assumption that the initial forces and the 

 lateral friction are negligible. He divided the motion into two parts, 

 that is, the pure drift currents and the relative currents, and showed 



