Carbon dioxide and methane dynamics in estuaries

We carried out a literature overview to synthesize current knowledge on CO2 and CH4 dynamics and fluxes with the atmosphere in estuarine environments. Estuarine systems are highly dynamic in terms of carbon cycling and emit CO2 to the atmosphere at rates that are quantitatively significant for the global C cycle. This emission of CO2 to the atmosphere is strongly supported by the net heterotrophic nature of these ecosystems. The robustness of the evaluation of the emission of CO2 from estuarine ecosystems has increased in last years due to increasing data availability and improvements in the surface area estimates by types. At present, the lack of sufficient data is the major limitation in the quantification of the spatial and temporal variability of CO2 fluxes in estuarine environments. Regarding future observations, there is also a need for sustained measurements to unravel inter-annual variability and long-term trends of CO2 and CH4 in estuarine environments. Indeed, due to the strong linkage with river catchements, inter-annual variability of CO2 and CH4 in estuarine environments is expected to be strong. Data used in the present synthesis were either obtained by the authors, data mined from publications or communicated by colleagues. There is a need for publicly available and quality checked data-bases for CO2 and CH4 in estuarine environments. Not only cross-system meta-analysis of data (CO2, CH4, O2, …) can be enlightening as explored in the present work, but also considering the uncertainties in the evaluation of the gas transfer velocity, there could be a need for future re-evaluations of air-water CO2 and CH4 fluxes, requiring access to the raw pCO2 and [CH4] data

Innovación tecnológica y metodológica en educación

Este proyecto de investigación, desarrollo e innovación (I+D+i) se centra tanto en las tecnologías innovadoras vinculadas a la educación digital como en los procesos de evaluación de dichas tecnologías aplicadas a la educación. En el marco del presente y considerando que las tecnologías actuales implican un impacto en los modelos educativos, se investiga sobre realidad aumentada (RA), realidad virtual (RV), hologramas y escenarios híbridos y se indaga en la mejora de procesos educativos a partir de la aplicación de las tecnologías mencionadas, sobre las competencias digitales docentes y la calidad y evaluación de la educación digital.Red de Universidades con Carreras en Informátic

Variability of the gas transfer velocity of CO2 in a macrotidal estuary (The Scheldt)

We report a large set of 295 interfacial carbon dioxide (CO2) flux measurements obtained in the Scheldt estuary in November 2002 and April 2003, using the floating chamber method. From concomitant measurements of the air-water CO2 gradient, we computed the gas transfer velocity of CO2. The gas transfer velocity is well correlated to wind speed and a simple linear regression function gives the most consistent fit to the data. Based on water current measurements, we estimated the contribution of water current induced turbulence to the gas transfer velocity, using the conceptual relationship of O’Connor and Dobbins (1958). This allowed us to construct an empirical relationship to compute the gas transfer velocity of CO2 that accounts for the contribution of wind and water current. Based on this relationship, the spatial and temporal variability of the gas transfer velocity in the Scheldt estuary was investigated.Water currents contribute significantly to the gas transfer velocity, but the spatial and temporal variability (from daily to seasonal scales) is mainly related to wind speed variability.Bioges

Comparison of Different Air–Water Gas Exchange Models to Determine Gaseous Mercury Evasion from Different European Coastal Lagoons and Estuaries

International audienceno abstrac