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Dissolved Inorganic Carbon in Rivers Teles Pires and Cristalino

Higo José Dalmagro, UNEMAT, higo@cpd.ufmt.br
Kelli Cristina Aparecida Munhoz, UNEMAT, kwmm@terra.com.br (Presenting)
Cristiane Akemi Umetsu, UNEMAT, cris_umetsu@yahoo.com.br
Alex Vladimir Krusche, CENA, alex@cena.usp.br
Maria de Fátima Fernandes Lamy Rasera, CENA, mrasera@cena.usp.br
Alexandra Ayres Montebello, CENA, mayres@cena.usp.br

The rivers are extremely important in the carbon cycle, either in the CO2 outgassing flows or carbon exporters to the oceans. Direct measuring of CO2 exchanges between the terrestrial ecosystems and the atmosphere should consider the aquatic systems flows, not overestimating the carbon terrestrial accumulation. The Amazon basin has the largest and more complex system of fresh water in the world, so that it holds an important place in the global carbon cycle. The objective of this work was to evaluate, during the period between September 2004 and August 2005, the dynamics of the species of the carbonate system (DIC = “free” CO2 + HCO3- + CO32-), dissolved in the waters of Teles Pires and Cristalino rivers, components of the Amazon basin, in the district of Alta Floresta, MT. Fortnightly were determined the inorganic carbon concentration dissolved total, pH and temperature of the rivers. Based in those results and applying the thermodynamic balance equations, it was possible to estimate the pCO2 and the carbonate system fractions. The rivers presented a seasonal variation in the pH values, being closer to the neutrality in the drought period. The concentration of HCO3- it was significantly larger in the drought than during the flood season. Both studied rivers were oversaturated in CO2 related to the atmosphere.

Science Theme:  CD (Carbon Dynamics)

Presentation Type:  Poster

Abstract ID: 83

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