@article{fdi:010060455,
  title = {{C}ross-shelf variability in the {I}berian {P}eninsula {U}pwelling {S}ystem : impact of a mesoscale filament},
  author = {{R}ossi, {V}. and {G}arcon, {V}. and {T}assel, {J}. and {R}omagnan, {J}. {B}. and {S}temmann, {L}. and {J}ourdin, {F}. and {M}orin, {P}. and {M}orel, {Y}ves},
  editor = {},
  language = {{ENG}},
  abstract = {{B}ased on a multidisciplinary survey in the {I}berian upwelling during late summer 2007, this paper analysed comparatively the cross-shore variability and offshore transport across the upwelling front and within a mesoscale filament. {A}long the {E}ast-{W}est ({EW}) sections, transient upwelling pulses bring regularly cold, fresh and nutrient-enriched waters to the surface, triggering intense biological responses. {O}ffshore advection by wind-forced {E}kman drift of the successive fronts, interrupted by relaxation periods, drive the variability of the planktonic communities. {W}hile the near-shore areas are dominated by relatively small phytoplankton controlled by mesozooplankton grazing, large cells of diatoms appear after a short decay. {A}lthough microphytoplankton dominates largely the shelf communities, the species composition varies during the offshore drift with the apparition of dinoflagellates and the gradual development of large zooplankton individuals. {T}he oligotrophic ecosystem characterised by small organisms and low biomass (similar to 80 km offshore) contrasts strongly with the transitional area and the coastal upwelling. {T}he low density waters within the filament and the existence of a pair of opposite rotating eddies at its base and tip promote its generation and rapid seaward extension. {T}he intensified offshore advection of coastal enriched waters considerably increases the area favouring a productive ecosystem (until similar to 160 km off the coast). {C}ross-shelf variability of bio-physical variables is observed in the filament as along {EW} sections, although a subsequent homogenisation within the mesoscale structure erases the sharp fronts. {O}ff the shelf within the filament, the chlorophyll a is distinctly organised as a shallow subsurface maximum dominated by nano-phytoplankton. {T}he relative physical isolation of a dynamical food-web in the filament is also promoting nutrient remineralisation under the structure. {F}inally, we estimate that mesoscale filaments, although being less extended meridionally than the upwelling front itself (similar to 40% of the length of the front) are responsible for a greater offshore transport of chlorophyll (similar to 60% of total cross-shelf exchanges) over the {I}berian system. {D}espite the favourable wind pulses advecting westward the successive upwelling fronts, self-propelled filaments provide permanent offshore transport, even under wind relaxation period, thus playing a major role in cross-shelf exchanges.},
  keywords = {{I}berian {P}eninsula {U}pwelling ; {C}ross-shore variability ; {U}pwelling front ; {M}esoscale filament ; {B}iogeochemistry ; {P}lanktonic community ; {ATLANTIQUE} ; {ATLANTIQUE} {ILES} ; {CANARIAS} ; {PORTUGAL} ; {ESPAGNE}},
  booktitle = {},
  journal = {{C}ontinental {S}helf {R}esearch},
  volume = {59},
  numero = {},
  pages = {97--114},
  ISSN = {0278-4343},
  year = {2013},
  DOI = {10.1016/j.csr.2013.04.008},
  URL = {https://www.documentation.ird.fr/hor/fdi:010060455},
}