Figure 3: 3D structure of the oceanic eddies.

3D structures of the horizontal velocity for (a) AE0, (b) CE and (c) AE1. Shading and black arrows denote the velocity magnitude and velocity vectors (in m/s), respectively. Note that velocity at different depths has different amplitude scales. The velocity amplitudes at 100, 500, 1000, 1500 and 2000 m have an amplifying ratio 1, 3, 5, 8 and 15, respectively. Green dotted line is the z-axis of the coordinate. Eddy centers at each layer, which are defined at the point of minimum velocity magnitude, are indicated by the purple dots. Edges of eddy core at each layer, which are defined at the radial positions of maximum velocity magnitude, are indicated by the green circles. Purple dotted line denotes the axis of eddy, defined as the line connecting the eddy centers at each layer. Purple arrow shows the drift of eddy center from the z-axis at the depth of 2000 m. Green arrow denotes the direction of the local topography gradient. Figures are plotted using MATLAB R2013a (http://www.mathworks.com/).