@article{fdi:010048345,
  title = {{H}igh-resolution regional ocean dynamics simulation in the southwestern tropical {A}tlantic},
  author = {{S}ilva, {M}. and {A}raujo, {M}. and {S}ervain, {J}acques and {P}enven, {P}ierrick and {L}entini, {C}. {A}. {D}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he southwestern tropical {A}tlantic (05 degrees {S}-25 degrees {S}/20 degrees {W}-47 degrees {W}), where part of the {S}outh {E}quatorial {C}urrent ({SEC}) enters at its eastern border, is of particular interest as it is fed by many western boundary currents along the eastern {B}razilian continental shelf. {H}owever, the long-term variability of the dynamics in this region, which are also important as they contribute to the climate over northeastern {B}razil, is largely unknown. {W}e use the {R}egional {O}cean {M}odel {S}ystem ({ROMS}) here for the first time in this area to simulate the ocean circulation with an isotropic horizontal grid resolution of 1/12 degrees and 40 terrain-following layers. {A}s a primary evaluation of the {ROMS} configuration, we explore surface and vertical thermal structures, the surface mixed layer, and mass transports within the upper levels. {I}nterannual variability results are compared with the first two-year series of observed thermal profiles derived from the three {PIRATA}-{SWE} moorings. {T}he simulated thermal structure in the upper ocean layers agrees well with in-situ data. {ROMS} simulations point out a broad and relatively weak {SEC} flow composed of a sequence of more or less defined near-surface cores. {T}he westward {SEC} transport for the upper 400 m along the {PIRATA}-{SWE} section, calculated from the {ROMS} simulation for 2005-2007, shows an average volume transport of 14.9 {S}v, with a maximum observed in {JFM} (15.7 {S}v), and a minimum during {MJJ} (13.8 {S}v). {ROMS} results indicate that the 2005-2007 seasonal near-surface westward {SEC} transport is modulated by the zonal wind variability. {T}hree zonal sections extending from the {A}merican continent to the {PIRATA} buoy sites confirm that stronger northward {NBUC} transport and decreasing {BC} transport were achieved during {M}ay 2006 and {M}ay 2007, i.e. at the time the s{SEC} bifurcation reaches its southernmost position. {O}n the other hand, the maximum southward {BC} flow was verified during {J}anuary 2006, {J}anuary 2007 and {M}arch 2007, with a minimum northward {NBUC} flow in {D}ecember 2005 and {O}ctober/{D}ecember 2006, corresponding to the period when the s{SEC} bifurcation reaches its lowest latitude ({OND}). {S}ea {S}urface {H}eight ({SSH}) and the surface {E}ddy {K}inetic {E}nergy ({EKE}) derived from simulations and {AVISO} {R}io05 product point out the highest surface meso-scale activity ({EKE} >= 50 cm(2) s(-2)) along the c{SEC} and {NBUC}/{BC} patches. {P}reliminary results provide additional ingredients in the complexity of the {SEC} divergence region and encourage us to conduct a more detailed exploration of the dynamics of this region using the {ROMS}. {T}his also shows the need to continue, extend, and vertically upgrade the observational {PIRATA}-{SWE} array system, especially with more levels of salinity measurements and the installation of current measurements.},
  keywords = {{S}outhwestern tropical {A}tlantic ; {U}pper ocean ; {PIRATA}-{SWE} moorings ; {ROMS} ; {S}outh equatorial current},
  booktitle = {},
  journal = {{O}cean {M}odelling},
  volume = {30},
  numero = {4},
  pages = {256--269},
  ISSN = {1463-5003},
  year = {2009},
  DOI = {10.1016/j.ocemod.2009.07.002},
  URL = {https://www.documentation.ird.fr/hor/fdi:010048345},
}