of the current system. It may be replaced by a rigid surface 

 where the velocity vanishes (no friction at this boundary). There- 

 fore, the "zero layer" has to be considered as the depth D of our 

 model of wind driven ocean currents, and D is a function of x and y. 



Let f = 2co sincp be the Coriolis parameter, p the pressure, 

 u and v the horizontal components of the current velocity vector ~& 

 in the x and y direction, respectively, v [cm" gr sec ] the co- 

 efficient of eddy viscosity in the lateral, and /i. the coefficient 

 of eddy viscosity in the vertical direction, V the Laplace oper- 

 ator in the x-y plane and p the density. The hydrodynamic equa- 

 tions of steady horizontal motion are 



,2.. a. ^ 



pf v + /j. ^-f + V V 2 u - j| = 

 _ pfu+/1 i!| + I/V 2 v -|E = o, 



(1) 



dz' 



the hydrostatic equation 



d = "" gp ' 



and the equation of continuity 



du , dv 



y dz 



(2) 



(3) 



The system of hydrodynamic equations (1) to (3) together with 

 adequate boundary conditions provides the basis for a very general 

 solution, that is, to find the horizontal and the vertical distri- 

 bution of u and v. Although this solution is of great interest, 

 the mathematical analysis is too complicated. Therefore the 

 question of the horizontal mass transport may be considered only. 

 If the vertically integrated mass transport M, with the components 

 U, V is introduced as the dependent variable, 



8 



