Figure 5


Figure 5: Longitude-time plot at 18°S of wind curl stress from ERS-1/2 (in 10-7 Pa/m) (provided by CERSAT) (a); pycnocline depth anomalies estimated from TP/ERS (metres), (b); pycnocline depth anomalies from a quasi-geostrophic linear model (metres), (c); and sea level anomalies at the coast from tide gauge data (cm) (provided by TOGA Sea Level Center) (d). Negative values for pycnocline depth anomalies correspond to a deepening of the thermocline and a warming of the surface waters. The model was forced by the ERS-1/2 winds and its boundary conditions in the east correspond to thermocline depth anomalies along the South American coast between 10°S and 40°S. They were given by a high-resolution Eastern Boundary linear Model (EBM) forced by sea level data at the equator [Pizarro et al., 1999].