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| Titel |
Seasonal variability of carbon dioxide and methane in the rivers and lagoons of Ivory Coast (West Africa) |
| VerfasserIn |
Y. J. M. Koné, G. Abril, B. Delille, A. V. Borges |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250028820
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| Zusammenfassung |
| We report a data-set of carbon dioxide (CO2) and dissolved methane (CH4) in three rivers (Bia, Tanoé and Comoé) and five lagoons (Tendo, Aby, Ebrié, Potou and Grand-Lahou) of Ivory Coast (West Africa), during the four main climatic seasons (high dry season, high rainy season, low dry season and low rainy season). The surface waters of the three rivers were oversaturated in CO2 and CH4 with respect to atmospheric equilibrium, the seasonal variability of CO2 and CH4 seemed to be largely controlled by dilution during the flooding period. The strong correlation of CH4 concentrations with the partial pressure of CO2 (pCO2) confirm the dominance of a continental sources (from soils) for both CO2 and CH4 in these rivers. The largest CH4 over-saturations and diffusive air-water CH4 fluxes were observed in the Tendo and Aby lagoons that are permanently stratified systems (unlike the other 3 lagoons), leading to anoxic bottom waters favorable for a large CH4 production. In addition, these two stratified lagoons showed low pCO2 values due to high primary production, which suggests an efficient transfer of organic matter across the pycnocline. As a result, the stratified Tendo and Aby lagoons were respectively, a low source of CO2 to the atmosphere and a sink of atmospheric CO2 while the other 3 well-mixed lagoons were strong sources of CO2 to the atmosphere but lower sources of CH4 to the atmosphere. |
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