Air-sea CO2 fluxes and the controls on ocean surface pCO(2) seasonal variability in the coastal and open-ocean southwestern Atlantic Ocean: a modeling study

Type Article
Date 2015-10-12
Language English
Author(s) Arruda R.1, Calil P. H. R.1, Bianchi A. A.2, 3, Doney S. C.4, Gruber N.5, Lima I.4, Turi G.5
Affiliation(s) 1 : Univ Fed Rio Grande, Inst Oceanog, Lab Dinam & odelagem Ocean DinaMO, Rio Grande, RS, Brazil.
2 : Univ Buenos Aires, Dept Ciencias Atmosfera & Oceanos, Buenos Aires, DF, Argentina.
3 : Serv Hidrog Naval, Dept Oceanog, Buenos Aires, DF, Argentina.
4 : Woods Hole Oceanog Inst, Dept Marine Chem & Geochem, Woods Hole, MA 02543 USA.
5 : ETH, Inst Biogeochem & Pollutant Dynam, Zurich, Switzerland.
Source Biogeosciences (1726-4170) (Copernicus Gesellschaft Mbh), 2015-10-12 , Vol. 12 , N. 19 , P. 5793-5809
DOI 10.5194/bg-12-5793-2015
WOS© Times Cited 30
Abstract We use an eddy-resolving, regional ocean biogeochemical model to investigate the main variables and processes responsible for the climatological spatio-temporal variability of pCO(2) and the air-sea CO2 fluxes in the southwestern Atlantic Ocean. Overall, the region acts as a sink of atmospheric CO2 south of 30 degrees S, and is close to equilibrium with the atmospheric CO2 to the north. On the shelves, the ocean acts as a weak source of CO2, except for the mid/outer shelves of Patagonia, which act as sinks. In contrast, the inner shelves and the low latitude open ocean of the southwestern Atlantic represent source regions. Observed nearshore-to-offshore and meridional pCO(2) gradients are well represented by our simulation. A sensitivity analysis shows the importance of the counteracting effects of temperature and dissolved inorganic carbon (DIC) in controlling the seasonal variability of pCO(2). Biological production and solubility are the main processes regulating pCO(2), with biological production being particularly important on the shelves. The role of mixing/stratification in modulating DIC, and therefore surface pCO(2), is shown in a vertical profile at the location of the Ocean Observatories Initiative (OOI) site in the Argentine Basin (42 degrees S, 42 degrees W).
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Arruda R., Calil P. H. R., Bianchi A. A., Doney S. C., Gruber N., Lima I., Turi G. (2015). Air-sea CO2 fluxes and the controls on ocean surface pCO(2) seasonal variability in the coastal and open-ocean southwestern Atlantic Ocean: a modeling study. Biogeosciences, 12(19), 5793-5809. Publisher's official version : https://doi.org/10.5194/bg-12-5793-2015 , Open Access version : https://archimer.ifremer.fr/doc/00293/40373/