@article{fdi:010081461,
  title = {{S}urface circulation and vertical structure of upper ocean variability around {F}ernando de {N}oronha {A}rchipelago and {R}ocas {A}toll during spring 2015 and fall 2017},
  author = {da {S}ilva, {A}. {C}. and {C}haigneau, {A}lexis and {D}ossa, {A}. {N}. and {E}ldin, {G}{\'e}rard and {A}raujo, {M}. and {B}ertrand, {A}rnaud},
  editor = {},
  language = {{ENG}},
  abstract = {{U}sing current, hydrographic and satellite observations collected off {N}ortheast {B}razil around the {F}ernando de {N}oronha {A}rchipelago and {R}ocas {A}toll during two oceanographic cruises (spring 2015 and fall 2017), we investigated the general oceanic circulation and its modifications induced by the islands. {I}n spring 2015, the area was characterized by lower {SST} (26.6 degrees {C}) and deep mixed-layer (similar to 90 m). {A}t this depth, a strong current shear was observed between the central branch of the eastward flowing near-surface {S}outh {E}quatorial {C}urrent and the westward flowing {S}outh {E}quatorial {U}ndercurrent. {I}n contrast, in fall 2017, {SST} was higher (similar to 28.8 degrees {C}) and the mixed-layer shallower (similar to 50 m). {T}he shear between the central {S}outh {E}quatorial {C}urrent and the {S}outh {E}quatorial {U}ndercurrent was weaker during this period. {I}nterestingly, no oxygen-rich water from the south (retroflection of the {N}orth {B}razil undercurrent) was observed in the region in fall 2017. {I}n contrast, we revealed the presence of an oxygen-rich water entrained by the {S}outh {E}quatorial {U}ndercurrent reaching {R}ocas {A}toll in spring 2015. {B}eside these global patterns, island wake effects were noted. {T}he presence of islands, in particular {F}ernando de {N}oronha, strongly perturbs central {S}outh {E}quatorial {C}urrent and {S}outh {E}quatorial {U}ndercurrent features, with an upstream core splitting and a reorganization of single current core structures downstream of the islands. {N}ear islands, flow disturbances impact the thermohaline structure and biogeochemistry, with a negative anomaly in temperature (-1.3 degrees {C}) and salinity (-0.15) between 200 and 400 m depth in the southeast side of {F}ernando {N}oronha (station 5), where the fluorescence peak (>1.0 mg m(-3)) was shallower than at other stations located around {F}ernando de {N}oronha, reinforcing the influence of flow-topography. {S}atellite maps of sea-surface temperature and chlorophyll-a confirmed the presence of several submesoscale features in the study region. {A}ltimetry data suggested the presence of a cyclonic mesoscale eddy around {R}ocas {A}toll in spring 2015. {A} cyclonic vortex (radius of 28 km) was actually observed in subsurface (150-350 m depth) southeast of {R}ocas {A}toll. {T}his vortex was associated with topographically induced {S}outh {E}quatorial {U}ndercurrent flow separation. {T}hese features are likely key processes providing an enrichment from the subsurface to the euphotic layer near islands, supplying local productivity.},
  keywords = {mesoscale activity ; satellite data ; western tropical {A}tlantic ; shipboard ; measurements ; island wake ; central {S}outh {E}quatorial {C}urrent ; {S}outh {E}quatorial {U}ndercurrent ; {ATLANTIQUE} ; {BRESIL} ; {ZONE} {TROPICALE} ; {ZONE} {EQUATORIALE} ; {FERNANDO} {DE} {NORONHA} {ARCHIPEL} ; {ROCAS} {ATOLL}},
  booktitle = {},
  journal = {{F}rontiers in {M}arine {S}cience},
  volume = {8},
  numero = {},
  pages = {598101 [16 ]},
  year = {2021},
  DOI = {10.3389/fmars.2021.598101},
  URL = {https://www.documentation.ird.fr/hor/fdi:010081461},
}