Figure 3-3 (left panel) shows the typical horizontal structure of continuous modes for log E=-0.20, 3.70 ≤ c ≤ 4.27. A blue filled circle in right panel indicates the position of the mode. In this case, a north boundary Kelvin mode (N.B.K.) like structure, the structure of a continuous mode (C), and an equatorial Kelvin wave (K) like structure are clearly observed.
The critical latitude of the mode shown in figure 3-3 is y=2.03. The amplitude peak of geopotential at y=2.10 shown in the left panel of figure 3-3 corresponds to the structure of continuous mode.
The amplitude peak of geopotential at y=3.00 is considered to correspond to a structure of north boundary Kelvin mode. The reasons are that phase speed of north boundary Kelvin mode is about 4 (indicated by an open triangle in the right panel of figure 3-3) which almost equals phase speed of the mode shown in figure 3-3, and that the structure trapped near the north boundary shows a boundary Kelvin wave like structure.
An equatorial Kelvin wave like structure appears around y=0.00 more clearly than figure 3-2. As stated in figure 3-2, it is considered that an equatorial Kelvin wave like structure is mixing into the continuous mode shown in this figure due to resonance with equatorial Kelvin modes and continuous modes.
There is a possibility that, similar to figure 3-2, structures of eastward inertial gravity modes and/or eastward mixed Rossby-gravity modes are mixing into the continuous mode of figure 3-3. However, it is not confirmed whether such mixing truly occurs or not only with figure 3-3.
Figure 3-3: Horizontal structure of a continuous mode for log E=-0.20, k=0.10, c=4.03 (left panel). The position of the mode in dispersion curves is indicated by a blue filled circle in the right panel. Contours and vectors in the left panel indicate &phi and velocity field, respectively. Contour intervals are 1.20 × 10-1. Other symbols in the right panel are same as table 1.