Sverdrup streamfunction for the period Aug 1991 through Jul 2000 from the FSU (top) and ERS (bottom) winds (10⁶ m³ s^-1). Bottom panel shows the difference (ERS–FSU). While the FSU winds suggest weak streamfunction gradients near the equator, with correspondingly weak vertically-integrated flow, the band of positive curl due to the TIW gives a band of negative ERS streamfunction and implies strong flows near the equator.