Autor(es): Barbosa, Pedro Maia ; Melack, John M. ; Farjalla, Vinícius Fortes ; Amaral, João Henrique Fernandes ; Scofield, Vinicius ; Forsberg, Bruce Rider
Data: 2020
Origem: Oasisbr
Assunto(s): Concentration (composition); Flux Measurement; Measurement Method; Methane; River Channel; Spatio-temporal Analysis; Tributary; Water Level; Amazon Basin; Amazonas; Brasil; Madeira River; Rio Negro Basin; Solimoes River
The first extensive set of measurements of methane concentrations and fluxes for the Negro River and its major tributaries combined with complementary data for the Solimões and Madeira rivers and several tributaries are presented and their temporal and spatial variations examined. Fluxes were measured using floating chambers, and dissolved CH4 concentrations were measured by the headspace technique. In the Solimões basin, tributaries had higher fluxes when water levels were low; no statistical difference among periods for lakes and the main stem river was observed. In the Negro basin, rivers had higher fluxes with greater variations among rivers during high water than during low water based on fluxes calculated from the concentration gradient and modelled gas transfer coefficients. We estimate a regional methane emission of 0.31 Tg C yr−1 for large river channels in the lowland Amazon basin. © 2016 Association for the Sciences of Limnology and Oceanography
