Circulation in the central equatorial Atlantic: Mean and intraseasonal to seasonal variability

The zonal equatorial circulation of the upper 700 m in the central tropical Atlantic is studied based on 11 cross-equatorial ship sections taken at 23-29 degrees W during 1999 to 2005 and on data from a pair of moored Acoustic Doppler current profilers deployed on the equator at 23 degrees W during February 2004 to May 2005. The observations on the equator reveal the existence of two mean westward cores of the Equatorial Intermediate Current below the Equatorial Undercurrent. In contrast to the 2002 moored observations at the same position the intraseasonal variability during the mooring period is dominated by zonal instead of meridional velocity fluctuations.