@article{fdi:010074852,
  title = {{O}n the variability in the {CO}2 system and water productivity in the western tropical {A}tlantic off {N}orth and {N}ortheast {B}razil},
  author = {{A}raujo, {M}. and {N}oriega, {C}. and {M}edeiros, {C}. and {L}ef{\`e}vre, {N}athalie and {I}banhez, {J}. {S}. {P}. and {M}ontes, {M}. {F}. and da {S}ilva, {A}. {C}. and {S}antos, {M}. {D}.},
  editor = {},
  language = {{ENG}},
  abstract = {{A} high-resolution nutrient biochemistry and carbonate system surface synoptic data set from the {N}-{NE} {B}razilian continental shelf was reanalyzed to fill a gap in the time series of the carbonate system in the region and to allow us to perform a historical analysis of its evolution in recent years. {W}e used data collected from 7 oceanographic cruises (n = 852) undertaken between {M}arch 1995 and {S}eptember 2001 during the {B}razilian {P}rogram "{REVIZEE}" in the {N}orth ({N}) and {N}ortheast ({NE}) {E}conomical {E}xclusive {Z}ones of {B}razil. {M}easured temperature and salinity data, which exhibited strong fluctuations (25.5 degrees {C} - 29.5 degrees {C} and 13.2-37.4 units, respectively), showed significant differences between the {N} and {NE} campaigns. {T}he concentrations of dissolved inorganic nitrogen ({DIN}), {PO}4- and {S}i{O}2- were higher in the {N} region than in the {NE} region, mainly due to fluvial transport, and nitrogen: phosphorus ({N}:{P}) ratios of < 16 and oxygen supersaturation were observed within the {A}mazon plume. {T}he concentrations of riverine nutrients in the {N} region support primary production occurring in the offshore plume area. {T}he calculated total alkalinity (1031-2437 mol kg(-1)) values showed strong spatial variations that were mainly associated with the {A}mazon plume. {T}he calculated p{CO}(2) values reached 423 mu atm offshore in the {NE} region during boreal winter. {T}he calculated sea-air {CO}2 fluxes (average: + 0.3 +/- 1.7 mmol m(-2) d(-1); range: -1.2 to + 2.0 mmol m(-2) d(-1)) showed spatial and temporal variations, with negative values (sink) in the region of the {A}mazon {R}iver plume and positive values (source) offshore in the {NE} region (4 degrees {S} to 12 degrees {S}). {T}he variability in the sea-air {CO}2 fluxes in the {N} and {NE} regions was explained by variations in biological activity and the thermodynamic effect of temperature, respectively. {T}he analysis of available data, complemented with those presented here, indicated that the surface water p{CO}(2) values showed a positive temporal trend (+ 1.10 +/- 0.2 mu atm yr(-1)) in the {NE} region during the period of 1987-2010. {T}his rate of increase is lower than that verified to have occurred in the atmosphere (+1.72 +/- 0.01 mu atm yr(-1)) during the same period.},
  keywords = {{C}arbonate system ; {S}ea-air {CO}2 fluxes ; {T}ropical {A}tlantic ; {T}ropical ocean ; productivity ; {REVIZEE} program ; {B}razilian continental shelf ; {ATLANTIQUE} ; {BRESIL} ; {ZONE} {TROPICALE}},
  booktitle = {},
  journal = {{J}ournal of {M}arine {S}ystems},
  volume = {189},
  numero = {},
  pages = {62--77},
  ISSN = {0924-7963},
  year = {2019},
  DOI = {10.1016/j.jmarsys.2018.09.008},
  URL = {https://www.documentation.ird.fr/hor/fdi:010074852},
}