In this work the Equatorial Atlantic Ocean circulation dynamics for warm and cold composite events are analyzed. Warm and cold typical years were composited from the respective five warmest and the five coldest years of the available record. Equatorial currents velocity and transport are calculated. During a typical warm event, the circulation decreases in the upper ocean, while during the typical cold event there is intensification. The strengthening (weakening) of the circulation during cold events increases (decreases) the stress between the Equatorial Undercurrent (EUC) and the South Equatorial Current (SEC), associated with an increase (decrease) in entrainment of cold waters into the surface and their westward transport. The EUC showed striking differences between both composited events. For the cold (warm) event the EUC shows a greater (reduced) transport and core velocity, and a deeper (shallower) structure.