Establishment of the Abyssal Circulation
421
i
l~~
1'
"' ~
,----------------------,Y=L
a-¥-0
0
0 0 w
0 0
--r--------------------------r--y=O
X=O
X= Xe
Fig. 7.6.1. Two-layer model of Kawase (1987) for the abyssal circulation. A cross-interface velocity
w balances the source of deep water Q which enters the abyss in the northwest corner of the basin.
The basin straddles the equator and the P-plane approximation is used so that f = f3y
P2 =PI + (]og'h
where
The linearized equation for mass conservation for the lower layer is:
ah +Hz [au2 + avz] = -w
at
ax ay
(7.6.3)
(7.6.4)
where w is the cross-interface velocity at the interface, z = h. In the absence of
wind driving and Ekman pumping there is no exchange through the upper