Follow this link to skip to the main content NASA Jet Propulsion Laboratory California Institute of Technology JPL HOME EARTH SOLAR SYSTEM STARS & GALAXIES SCIENCE & TECHNOLOGY BRING THE UNIVERSE TO YOU JPL Email News RSS Podcast Video
JPL Banner
Ocean Surface Topography from Space
Interannual variability and regional impacts in the Tropical Atlantic Ocean

Homogeneous correlation maps
Homogeneous correlation maps of the τX and τy components of the 4th Singular Value Decomposition (SVD) of the low-frequency altimetry Absolute Dynamic Topography (ADT) and wind stress data (map for τX followed by map for τy , top). The colors correspond to the correlation between the altimetry data and τX and τy. The arrows are the SVD ouput of the wind-altimetry SVD analysis in which the wind components are not treated independently. Homogeneous correlation map of the altimetry ADT component of the 4th SVD of the low-frequency altimetry ADT and wind stress data (middle). Color scale is from r=[-1 1]. Corresponding SVD scores for ADT (red) and wind stress (blue) (bottom). From Arnault and Melice, 2012. Superimposed (black circle) are the 4 regions to be complementary investigated in a local context.

Sabine Arnault - (LOCEAN)

Co-Principle Investigator: Bernard Bourles (LEGOS)

  Pierrick Penven
Angora Aman
Fabrice Papa
Remy Chuchla
Yves Dupenhoat
Jean-Luc Melice
Sylvie Thiria
Awa Niang
Regina Folorunsho
(Laboratory of Atmospheric Physics and Fluid Mechanics)
(Nigerian Institute for Oceanography and Marine Research)


Contrary to the Pacific Ocean, where the dominant mode of variability, the El Niño-Southern Oscillation (ENSO), occurs on an interannual timescale, the dominant mode of variability in the tropical Atlantic Ocean occurs mainly on annual timescales. Moreover, the large scale variability of the Atlantic is much more complex than the Pacific one, both in time and space. It is usually split into an interannual variability, with equatorial warm events analogous to, but weaker than, the ENSO and into decadal timescale of variability, with sea-surface temperature (SST) varying almost in opposition north and south of the equator. Many mechanisms of the large scale variability of the tropical Atlantic are not well understood and are still under debate. For instance, is the ocean by itself playing a major role in the decadal variability? Is this variability limited to a few regions only or to the entire Atlantic basin? Remote forcings versus local forcings of this large scale variability also raise controversial theories about the ENSO influence, the North Atlantic Oscillation (NAO) or the southern Ocean forcings.

Altimetry, and more generally satellite missions, is interesting as it covers the global ocean. New missions such as the next coming SARAL/Altika altimetry mission, or the future SWOT mission, are some promising and challenging tools to approach coastal oceanography.

The aim of this OSTST proposal is thus to analyse the large scale variability of the tropical Atlantic, on an interannual basis, from the series of TOPEX/Poseidon, Jason1&2 data covering the 1993-2012 period, and to benefit from the new generation of altimetry missions to focus on the local impacts/variability over some key regions: the western coast, the Gulf of Guinea, and the Dakar and Benguela upwelling areas.

Link to
Site Manager: Margaret Srinivasan
Webmaster: Kristy Kawasaki
JPL Clearance: CL01-1707