@article{fdi:010060679,
  title = {{C}anary current upwelling : more or less ?},
  author = {{B}arton, {E}. {D}. and {F}ield, {D}. {B}. and {R}oy, {C}laude},
  editor = {},
  language = {{ENG}},
  abstract = {{I}t has been hypothesized that coastal upwelling in the four major eastern boundary current systems might be intensified as global warming could result in a greater land-sea temperature gradient and hence strengthen alongshore winds. {R}ecent research has suggested a substantial increase of upwelling intensity off {N}orthwest {A}frica. {E}vidence there is based on the derivation of a proxy for upper ocean temperatures from the alkenone unsaturation index ({U}-37({K})') derived from two sediment cores recovered off {C}ape {G}hir, {M}orocco. {A}n accelerating decrease of over 1 degrees {C} during the last century was concluded for near surface temperature near the {C}ape. {S}upport for this conclusion was found in an increase in {B}akun's upwelling index for the same area. {T}he evidence for a general intensification of upwelling within the whole {C}anary current upwelling system is examined here. {U}sing available estimates of wind from {PFEL}, {NCAR}/{NCEP}, {ECMWF}, {ICOADS} and {WASW}ind plus measured wind data from coastal meteorological stations, no evidence of a coherent intensification in winds at the regional scale off {N}orthwest {A}frica is found. {M}oreover, sea surface temperature records from ships-of-opportunity ({ICOADS} data set) and also from the {P}athfinder satellite {AVHRR} data set show a significant and correlated increase at all latitudes in the region, including in the area around {C}ape {G}hir. {I}t is concluded that there is no evidence for a general increase in upwelling intensity off {N}orthwest {A}frica or {I}beria. {T}he apparent lowering of {SST} off {C}ape {G}hir indicated by the,alkenone unsaturation index can be explained by coccolithophorids (phytoplankton from which the {U}-37({K})' signal is derived) living deeper in the water column. {T}he distribution of most phytoplankton (including coccolithophorids) will deepen and have less overlap with mixed layer temperatures as the ocean warms, resulting in a near surface temperature estimate that is increasingly biased by subsurface temperatures and lower than the actual {SST}.},
  keywords = {{CANARIES}},
  booktitle = {},
  journal = {{P}rogress in {O}ceanography},
  volume = {116},
  numero = {},
  pages = {167--178},
  ISSN = {0079-6611},
  year = {2013},
  DOI = {10.1016/j.pocean.2013.07.007},
  URL = {https://www.documentation.ird.fr/hor/fdi:010060679},
}