Mean wind stress Curl for the period Aug 1991 through Jul 2000 from the FSU (top) and ERS (bottom) winds (10^-7 N m^-3. Bottom panel shows the difference (ERS–FSU).
The ERS ITCZ curl at 15-°E-160°W is shifted slightly equatorward and is weaker than the FSU curl, leading to a negative d(Curl(Tau))/dy and consequently weaker NECC in the west.