@article{fdi:010064656,
  title = {{D}ownscaling biogeochemistry in the {B}enguela eastern boundary current},
  author = {{M}achu, {E}ric and {G}oubanova, {K}aterina and {L}e {V}u, {B}. and {G}utknecht, {E}. and {G}arcon, {V}.},
  editor = {},
  language = {{ENG}},
  abstract = {{D}ynamical downscaling is developed to better predict the regional impact of global changes in the framework of scenarios. {A}s an intermediary step towards this objective we used the {R}egional {O}cean {M}odeling {S}ystem ({ROMS}) to downscale a low resolution coupled atmosphere-ocean global circulation model ({AOGCM}; {IPSL}-{CM}4) for simulating the recent-past dynamics and biogeochemistry of the {B}enguela eastern boundary current. {B}oth physical and biogeochemical improvements are discussed over the present climate scenario (1980-1999) under the light of downscaling. {D}espite biases introduced through boundary conditions (atmospheric and oceanic), the physical and biogeochemical processes in the {B}enguela {U}pwelling {S}ystem ({BUS}) have been improved by the {ROMS} model, relative to the {IPSL}-{CM}4 simulation. {N}evertheless, using coarse-resolution {AOGCM} daily atmospheric forcing interpolated on {ROMS} grids resulted in a shifted {SST} seasonality in the southern {BUS}, a deterioration of the northern {B}enguela region and a very shallow mixed layer depth over the whole regional domain. {W}e then investigated the effect of wind downscaling on {ROMS} solution. {T}ogether with a finer resolution of dynamical processes and of bathyrnetric features (continental shelf and {W}alvis {R}idge), wind downscaling allowed correction of the seasonality, the mixed layer depth, and provided a better circulation over the domain and substantial modifications of subsurface biogeochemical properties. {I}t has also changed the structure of the lower trophic levels by shifting large offshore areas from autotrophic to heterotrophic regimes with potential important consequences on ecosystem functioning. {T}he regional downscaling also improved the phytoplankton distribution and the southward extension of low oxygen waters in the {N}orthern {B}enguela. {I}t allowed simulating low oxygen events in the northern {BUS} and highlighted a potential up scaling effect related to the nitrogen irrigation from the productive {BUS} towards the tropical/subtropical {S}outh {A}tlantic basin. {T}his study shows that forcing a downscaled ocean model with higher resolution winds than those issued from an {AOGCM}, results in improved representation of physical and biogeochemical processes.},
  keywords = {{O}cean modeling ; {D}ownscaling ; {U}pscaling ; {U}pwelling ; {B}iogeochemistry ; {B}enguela ; {ROMS} ; {AFRIQUE} {DU} {SUD} ; {BENGUELA}},
  booktitle = {},
  journal = {{O}cean {M}odelling},
  volume = {90},
  numero = {},
  pages = {57--71},
  ISSN = {1463-5003},
  year = {2015},
  DOI = {10.1016/j.ocemod.2015.01.003},
  URL = {https://www.documentation.ird.fr/hor/fdi:010064656},
}