The Subpolar Gyre
217
N
Ps
Fig. 4.8.1. a Outcrop line of layer 4 in the subpolar gyre produced by Ekman suction acting on
layer 3. b Zonal cross section of the layer thicknesses along the dotted line in a. Note that the
thickness of layer 3 vanishes as the square root of the distance to the outcrop line
For example, when the Ekman suction velocity is independent of longitude,
<1>3 ( 8) is given by:
(4.8.3)
where the left side of (4.8.3) represents the linear distance to the eastern
boundary. The precise form of the curve on which the interface comes to the
surface depends on the structure of the Ekman suction. However, it is clear
that for all finite Ekman velocities the curve given by (4.8.3) does not reach the
eastern boundary. If wE increases northward from the intergyre boundary at
(} = 8o, the curve approaches the eastern boundary and if the Ekman suction
decreases further northward the curve swings back to the northwest, as shown
b
217
N
Ps
Fig. 4.8.1. a Outcrop line of layer 4 in the subpolar gyre produced by Ekman suction acting on
layer 3. b Zonal cross section of the layer thicknesses along the dotted line in a. Note that the
thickness of layer 3 vanishes as the square root of the distance to the outcrop line
For example, when the Ekman suction velocity is independent of longitude,
<1>3 ( 8) is given by:
(4.8.3)
where the left side of (4.8.3) represents the linear distance to the eastern
boundary. The precise form of the curve on which the interface comes to the
surface depends on the structure of the Ekman suction. However, it is clear
that for all finite Ekman velocities the curve given by (4.8.3) does not reach the
eastern boundary. If wE increases northward from the intergyre boundary at
(} = 8o, the curve approaches the eastern boundary and if the Ekman suction
decreases further northward the curve swings back to the northwest, as shown
b