Fig. 5 Composite anomaly maps of Argo 10 dbar potential temperature. Contour interval is 0.1 ◦C. Negative contours are dotted,and the first positive contour is at 0.05 ◦C. Shading is indicated by the legend. Anomalies that are statistically significant at the 90% level are delineated by a thick contour. Black shading denotes areas of land or missing data.