@article{fdi:010087494,
  title = {{R}evisiting the tropical {A}tlantic western boundary circulation from a 25-yeartime series of satellite altimetry data},
  author = {{D}imoune, {D}. {M}. and {B}irol, {F}. and {H}ernandez, {F}abrice and {L}eger, {F}. and {A}raujo, {M}.},
  editor = {},
  language = {{ENG}},
  abstract = {{G}eostrophic currents derived from altimetry are used to investigate the surface circulation in the western tropical {A}tlantic over the 1993-2017 period. {U}sing six horizontal sections defined to capture the current branches of the study area, we investigate their respective variations at both seasonal and interannual timescales, as well as the spatial distribution of these variations, in order to highlight the characteristics of the currents on their route. {O}ur results show that the central branch of the {S}outh {E}quatorial {C}urrent and its northern branch near the {B}razilian coast, the {N}orth {B}razil {C}urrent component located south of the {E}quator, and the {G}uyana {C}urrent have similar annual cycles, with maxima (minima) during late boreal winter (boreal fall) when the {I}ntertropical {C}onvergence {Z}one is at its southernmost (northernmost) location. {I}n contrast, the seasonal cycles of the {N}orth {B}razil {C}urrent branch located between the {E}quator and 7-8 degrees {N}, its retroflected branch, the northern branch of the {S}outh {E}quatorial {C}urrent to the west of 35 & {LCIRC}; {W}, and the {N}orth {E}quatorial {C}ountercurrent show maxima (minima) during late boreal summer (boreal spring), following the remote wind stress curl strength variation. {W}est of 32 degrees {W}, an eastward current (the {E}quatorial {S}urface {C}urrent, {ESC}) is observed between 2-2 degrees {N}, identified as the equatorial extension of the retroflected branch of the {N}orth {B}razil {C}urrent. {I}t is part of a large cyclonic circulation observed between 0-6 degrees {N} and 35-45 degrees {W} during boreal spring. {W}e also observed a secondary {N}orth {B}razil {C}urrent retroflection flow during the second half of the year, which leads to the two-core structure of the {N}orth {E}quatorial {C}ountercurrent and might be related to the wind stress curl seasonal changes. {T}o the east, the {N}orth {E}quatorial {C}ountercurrent weakens and its two-core structure is underdeveloped due to the weakening of the wind stress. {A}t interannual scales, depending on the side of the {E}quator examined, the {N}orth {B}razil {C}urrent exhibits two opposite scenarios related to the phases of the tropical {A}tlantic {M}eridional {M}ode. {A}t 32 degrees {W}, the interannual variability of the {N}orth {E}quatorial {C}ountercurrent and of the northern branch of the {S}outh {E}quatorial {C}urrent (in terms of both strength and/or latitudinal shift) are associated with the {A}tlantic {M}eridional {M}ode, whereas the variability of the {E}quatorial {S}urface {C}urrent intensity is associated with both the {A}tlantic {M}eridional {M}ode and {A}tlantic {Z}onal {M}ode phases.},
  keywords = {{ATLANTIQUE} ; {ZONE} {TROPICALE} ; {ATLANTIQUE} {OUEST}},
  booktitle = {},
  journal = {{O}cean {S}cience},
  volume = {19},
  numero = {2},
  pages = {251--268},
  ISSN = {1812-0784},
  year = {2023},
  DOI = {10.5194/os-19-251-2023},
  URL = {https://www.documentation.ird.fr/hor/fdi:010087494},
}