All- 101 2 



(11) A more general density distribution is then assumed, 

 but a more restrictive assumption is made concerning the verti- 

 cal variation of velocity. In particular, it is assumed that 

 there exists a (variable) depth below which the velocities are 

 negligible. As a result of this assumption, a direct relation 

 is found between the thermocline and the free surface. The 

 equations are integrated from this depth up to the free surface^ 

 The linearised equations are then subjected to an analytical 

 treatment consisting of a perturbation expansion in terms of a 

 parameter which is proportional to the frequency of the wind 

 variation. The resulting equations are solved by boundary 

 layer technique. 



Results are derived for the response of the mass trans- 

 port to slov;ly varying v;inds, and the effect of the wind on the 

 intensified stream near the western boundary is discussed in 

 detail. 



The two-layer steady problem is also solved and the 

 steady position of the thermocline is determined. 



