FIGURE T16. Mean (top) and anomalous (bottom) depth of the 20°C isotherm. Contour interval is 40 m (top) and 10 m (bottom). Dashed contours in bottom panel indicate negative anomalies. Data are derived from the NCEP’s global ocean data assimilation system which assimilates oceanic observations into an oceanic GCM (Behringer and Xue, Proceedings of Eighth Symposium on Integrated Observing and Assimilation Systems for Atmospher, Oceans, and Land Surface, Seattle, Washington, 11-15 January 2004). Anomalies are departures from the 1992–2003 base period means.