@article{fdi:010068178,
  title = {{S}easonal variability of the {E}kman transport and pumping in the upwelling system off central-northern {C}hile (~30 degrees {S}) based on a high-resolution atmospheric regional model ({WRF})},
  author = {{B}ravo, {L}. and {R}amos, {M}. and {A}studillo, {O}. and {D}ewitte, {B}oris and {G}oubanova, {K}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}wo physical mechanisms can contribute to coastal upwelling in eastern boundary current systems: offshore {E}kman transport due to the predominant alongshore wind stress and {E}kman pumping due to the cyclonic wind stress curl, mainly caused by the abrupt decrease in wind stress (drop-off) in a cross-shore band of 100a{E}uro-km. {T}his wind drop-off is thought to be an ubiquitous feature in coastal upwelling systems and to regulate the relative contribution of both mechanisms. {I}t has been poorly studied along the central-northern {C}hile region because of the lack in wind measurements along the shoreline and of the relatively low resolution of the available atmospheric reanalysis. {H}ere, the seasonal variability in {E}kman transport, {E}kman pumping and their relative contribution to total upwelling along the central-northern {C}hile region (~30 degrees {S}) is evaluated from a high-resolution atmospheric model simulation. {A}s a first step, the simulation is validated from satellite observations, which indicates a realistic representation of the spatial and temporal variability of the wind along the coast by the model. {T}he model outputs are then used to document the fine-scale structures in the wind stress and wind curl in relation to the topographic features along the coast (headlands and embayments). {B}oth wind stress and wind curl had a clear seasonal variability with annual and semiannual components. {A}longshore wind stress maximum peak occurred in spring, second increase was in fall and minimum in winter. {W}hen a threshold of -3 x 10(-5) s(-1) for the across-shore gradient of alongshore wind was considered to define the region from which the winds decrease toward the coast, the wind drop-off length scale varied between 8 and 45 km. {T}he relative contribution of the coastal divergence and {E}kman pumping to the vertical transport along the coast, considering the estimated wind drop-off length, indicated meridional alternation between both mechanisms, modulated by orography and the intricate coastline. {R}oughly, coastal divergence predominated in areas with low orography and headlands. {E}kman pumping was higher in regions with high orography and the presence of embayments along the coast. {I}n the study region, the vertical transport induced by coastal divergence and {E}kman pumping represented 60 and 40 % of the total upwelling transport, respectively. {T}he potential role of {E}kman pumping on the spatial structure of sea surface temperature is also discussed.},
  keywords = {{CHILI} ; {PACIFIQUE} {SUD}},
  booktitle = {},
  journal = {{O}cean {S}cience},
  volume = {12},
  numero = {5},
  pages = {1049--1065},
  ISSN = {1812-0784},
  year = {2016},
  DOI = {10.5194/os-12-1049-2016},
  URL = {https://www.documentation.ird.fr/hor/fdi:010068178},
}