Fig. 2

Hovmöller diagrams for the results in the last year of the climatological model experiment. The research areas are at a, b 35° N, 140°–130° W and c, d the equator, 120° E–70° W. Left panels a, c: color shading represents simulated zonal velocity \(u\) (with a unit of m/s) and contours represent zonal wind stress \(\tau_{wind}^{x}\) (with a contour interval of a 0.004 N/m², and c 0.02 N/m², all positive values are shown in solid lines and all negative values are shown in dashed lines). Right panels b, d: color shading represents simulated geopotential anomaly \(\frac{p}{c}\) which has been rescaled to be compared with the magnitude of velocity (with a unit of m/s) and contours represent pseudo-streamfunction \(\varphi\) inverted from Eq. (2b) (with a contour interval of b 50 m²/s, and d 4000 m²/s, all positive values are shown in solid lines and all negative values are shown in dashed lines)