542 



Currents in a Strait 



The vertical density distribution is assumed to correspond to that of the Reid model 

 (1948) 



P = Po; - ^ ^ z ^ h; p= pa-Ap e^-'^^ (h ^ z ^ d) (XVI.30) 

 where 



Ap= pd- Po and p = pd {d S z). 



This corresponds to a homogeneous top layer of thickness h with a lower layer in 

 which the density increases to p^. Then as a first approximation 



81: 2Ap 8h dP 5gAp 8h^ 



— ■ /->-' — and — '-^ ■ — 



8x Pq dx dx 2 dx 



Analogous equations will apply for y and furthermore 



(XVI.31) 



/l2=- 



5gAp 



P. 



(XIV.32) 



The integrated pressure P can be taken to represent the thickness of the upper homo- 

 genous layer. Putting /= in equation (XVI.29), that is, neglecting the CorioHs force 

 gives 



Fig. 25la. Schematic representation of the spreading of river water in the ocean off the 



river mouth. 



