Hovm ̈oller diagrams of the anomalous depth of the 20 ◦C isotherm from 1 January 2003 to 1 January 2007, averaged between
2
◦S and 2 ◦N, from (a) gridded Argo data, (b) TAO buoy data. Contour interval is 10 m; see legend for shading. The solid lines
indicate the propagation paths of positive eastward-propagating anomalies, and are identical in both panels. Equatorial OLR anomalies,
averaged from 10 ◦S to 10 ◦N, are hatched vertically below −15 W m−2 and diagonally above 15 W m−2
; see legend for hatching.