@article{fdi:010079858,
  title = {{F}rom mixing to the large scale circulation : how the inverse cascade is involved in the formation of the subsurface currents in the {G}ulf of {G}uinea},
  author = {{A}ssene, {F}. and {M}orel, {Y}. and {D}elpech, {A}. and {A}guedjou, {M}. and {J}ouanno, {J}ulien and {C}ravatte, {S}ophie and {M}arin, {F}r{\'e}d{\'e}ric and {M}enesguen, {C}. and {C}haigneau, {A}lexis and {D}adou, {I}. and {A}lory, {G}. and {H}olmes, {R}. and {B}ourl{\`e}s, {B}ernard and {K}och {L}arrouy, {A}riane},
  editor = {},
  language = {{ENG}},
  abstract = {{I}n this paper, we analyse the results from a numerical model at high resolution. {W}e focus on the formation and maintenance of subsurface equatorial currents in the {G}ulf of {G}uinea and we base our analysis on the evolution of potential vorticity ({PV}). {W}e highlight the link between submesoscale processes (involving mixing, friction and filamentation), mesoscale vortices and the mean currents in the area. {I}n the simulation, eastward currents, the {S}outh and {N}orth {E}quatorial {U}ndercurrents ({SEUC} and {NEUC} respectively) and the {G}uinea {U}ndercurrent ({GUC}), are shown to be linked to the westward currents located equatorward. {W}e show that east of 20 degrees {W}, both westward and eastward currents are associated with the spreading of {PV} tongues by mesoscale vortices. {T}he {E}quatorial {U}ndercurrent ({EUC}) brings salty waters into the {G}ulf of {G}uinea. {M}ixing diffuses the salty anomaly downward. {M}eridional advection, mixing and friction are involved in the formation of fluid parcels with {PV} anomalies in the lower part and below the pycnocline, north and south of the {EUC}, in the {G}ulf of {G}uinea. {T}hese parcels gradually merge and vertically align, forming nonlinear anticyclonic vortices that propagate westward, spreading and horizontally mixing their {PV} content by stirring filamentation and diffusion, up to 20 degrees {W}. {W}hen averaged over time, this creates regions of nearly homogeneous {PV} within zonal bands between 1.5 degrees and 5 degrees {S} or {N}. {T}his mean {PV} field is associated with westward and eastward zonal jets flanking the {EUC} with the homogeneous {PV} tongues corresponding to the westward currents, and the strong {PV} gradient regions at their edges corresponding to the eastward currents. {M}esoscale vortices strongly modulate the mean fields explaining the high spatial and temporal variability of the jets.},
  keywords = {equatorial atlantic ; {NEUC} ({N}orth {E}quatorial {U}ndercurrents) ; {SEUC} ({S}outh {E}quatorial {U}ndercurrents) ; vortices ; mixing ; friction ; {ATLANTIQUE} ; {GUINEE} {GOLFE} ; {ZONE} {EQUATORIALE}},
  booktitle = {},
  journal = {{F}luids},
  volume = {5},
  numero = {3},
  pages = {147 [34 p.]},
  year = {2020},
  DOI = {10.3390/fluids5030147},
  URL = {https://www.documentation.ird.fr/hor/fdi:010079858},
}