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Polsenaere, Pierre; Deborde, Jonathan; Detandt, Guillaume; Vidal, Luciana O.; Perez, Marcela A. P.; Marieu, Vincent; Abril, Gwenael. |
In November 2011, the partial pressures of carbon dioxide (pCO(2)) in water and air in a floodplain lake of the Amazon River in Brazil were 800 +/- 75 and 387 +/- 8 ppmv, respectively. Turbulent CO2 fluxes from the lake measured with eddy covariance ranged from 0.05 to 2.2 mmol m(-2) s(-1). The corresponding gas transfer velocities k(600) ranged from 1.3 to 31.6 cm h(-1), averaging 12.2 +/- 6.7 cm h(-1). At moderate to high wind speed, k(600) increased with wind speed, with values above parameterizations for other lake ecosystems. During the prevailing tropical low wind speed (below 2.7 m s(-1)) and high insolation conditions, unexpected high k(600) values (up to 20 cm h(-1)) were obtained and correlated with latent heat and sensible heat fluxes. In... |
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Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00603/71532/69950.pdf |
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Borges, Alberto V.; Abril, Gwenael; Darchambeau, Francois; Teodoru, Cristian R.; Deborde, Jonathan; Vidal, Luciana O.; Lambert, Thibault; Bouillon, Steven. |
Carbon emissions to the atmosphere from inland waters are globally significant and mainly occur at tropical latitudes. However, processes controlling the intensity of CO2 and CH4 emissions from tropical inland waters remain poorly understood. Here, we report a data-set of concurrent measurements of the partial pressure of CO2 (pCO(2)) and dissolved CH4 concentrations in the Amazon (n = 136) and the Congo (n = 280) Rivers. The pCO(2) values in the Amazon mainstem were significantly higher than in the Congo, contrasting with CH4 concentrations that were higher in the Congo than in the Amazon. Large-scale patterns in pCO(2) across different lowland tropical basins can be apprehended with a relatively simple statistical model related to the extent of wetlands... |
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Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00603/71528/69955.pdf |
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Deborde, Jonathan; Anschutz, Pierre; Chaillou, Gwenaelle; Etcheber, Henri; Commarieu, Marc-vincent; Lecroart, Pascal; Abril, Gwenael. |
Suspended particles and surface waters were collected in the Gironde estuary (southwestern France) along the salinity gradient. Dissolved inorganic phosphorus (DIP) was analyzed in the filtered surface waters. The suspended particles were sequentially leached to determine five fractions of phosphorus: exchangeable or loosely sorbed P, reactive Fe-bound P, refractory Fe oxide-bound P, P associated with apatite and carbonates, and organic P. Experiments were conducted to determine the effects of temperature, salinity, and DIP concentration on phosphorus sorption/desorption processes. The concentration and distribution of particulate phosphorus was homogeneous along the salinity gradient of the estuary, whereas it was variable in time and space in the... |
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Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00603/71538/69943.pdf |
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