Climate Dynamics

, Volume 43, Issue 11, pp 2943–2962

Mean meridional currents in the central and eastern equatorial Atlantic


    • Cooperative Institute for Marine and Atmospheric StudiesUniversity of Miami
    • NOAA Atlantic Oceanographic and Meteorological Laboratory
  • Verena Hormann
    • Scripps Institution of OceanographyUniversity of California, San Diego
  • Rick Lumpkin
    • NOAA Atlantic Oceanographic and Meteorological Laboratory
  • Peter Brandt
    • GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel
  • William E. Johns
    • Rosenstiel School of Marine and Atmospheric ScienceUniversity of Miami
  • Fabrice Hernandez
    • Institut de Recherche pour le Développement, Mercator-Océan
  • Claudia Schmid
    • NOAA Atlantic Oceanographic and Meteorological Laboratory
  • Bernard Bourlès
    • Institut de Recherche pour le Développement, LEGOS

DOI: 10.1007/s00382-013-1968-5

Cite this article as:
Perez, R.C., Hormann, V., Lumpkin, R. et al. Clim Dyn (2014) 43: 2943. doi:10.1007/s00382-013-1968-5


Ship-based acoustic Doppler current profiler (ADCP) velocity measurements collected by several major field programs in the tropical Atlantic are averaged and combined with estimates of the mean near-surface velocity derived from drifters and Argo float surface drifts (ADCP+D) to describe the mean cross-equatorial and vertical structure of the meridional currents along 23°W and 10°W. Data from moored ADCPs and fixed-depth current meters, a satellite-derived velocity product, and a global ocean reanalysis were additionally used to evaluate the mean ADCP+D meridional velocity. The dominant circulation features in the long-term mean ADCP+D meridional velocity in the upper 100 m are the tropical cells (TCs) located approximately between 5°S and 5°N, with near-surface poleward flow and subsurface equatorward flow that is stronger and shallower in the northern cell compared to the southern cell. The thickness of the surface limb of the TCs decreases and the northern cell is found to shift further south of the equator from the central to eastern tropical Atlantic. Analysis of two-season means estimated from the ship-based ADCP, near-surface drift, and moored velocity data, as well as the simulated fields, indicates that the maximum poleward velocity in the surface limb of the TCs intensifies during December–May along 23°W largely due to seasonal compensation between the geostrophic and ageostrophic (or wind-driven) components of the meridional velocity, whereas the maximum equatorward flow in the subsurface limb of the northern cell intensifies during June–November along both 23°W and 10°W due to the seasonality of the geostrophic meridional velocity.


Tropical AtlanticMeridional currentsTropical cells

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© Springer-Verlag Berlin Heidelberg 2013