Extended Data Fig. 6: Equatorial thermocline response in the CESM LOP simulations connects the western equatorial Pacific zonal wind stress change to cold tongue changes.
From: Two annual cycles of the Pacific cold tongue under orbital precession
LOP cases (a) 90°, (b) 180°, (c) 270°, and (d) 0° are shown. Contours show the 6°S–6°N averaged temperature anomaly at mean thermocline depth for e = 0.04, for the stated LOP. The temperature averaged across all LOP cases is first subtracted out, to remove the influence of the tilt effect from the thermocline. The contour interval is 0.5K, and dashed values are negative; the zero contour is not shown. For clarity, only values east of 170°E are plotted. The eastward propagation of thermocline anomalies is visually apparent. Shading represents the corresponding zonal wind stress anomaly averaged over 6°S–6°N; the average across all LOP cases is first subtracted out, to remove the influence of the tilt effect. Only values in the western Pacific (west of 160°W) are plotted. Positive values indicate westerlies. Although only four LOP cases are shown here, a deeper thermocline (as indicated by warmer temperature) in the western Pacific is accompanied by a westerly wind stress anomaly (and vice versa) for all LOP cases.
