Ail-lol 33 



layer problem (the vertical integration being carried out in 

 two steps). 



It may seem to the reader at this point that, since we 

 have integrated the equations of motion over the vertical coor- 

 dinate z in both problems , there is nothing to be gained by 

 considering Problem 2 in which the density distribution is more 

 specialized tha/t that of Problem 1. Because of the importance 

 of this point, we shall discuss the significance of the two 

 problems in more detail. 



Needless to say, the problem of greatest interest in- 

 cludes the more general density distribution of Problem 1, the 

 four independent coordinates XjyjZjt^ and the full non-linear 

 equations. The wind- stress components appear as the values of 

 the vertical shear at the free surface z = n(x,y,t). The solu- 

 tion of this problem would, of course, include complete inform- 

 ation concerning the dependence of the motion on z« Being 

 unable to attack this problem, we are forced to integrate the 

 equations over z and to content ourselves with a solution for 

 the transport componentso 



At first this integration over the vertical coordinate, 

 z, appears to have only one shortcoming, viz. , a loss of inform- 

 ation concerning the vertical distribution of velocity. We 

 cannot, however, completely afford such a loss of infornHtion 

 in the formulation of the "transport" problem and some recourse 

 to field evidence is necessary. Unfortunately, hov/ever, accur- 

 ate observational data are extremely difficult to obtain. In 

 particular, it is generally hold that the motion in the deep 



