Reservoirs are recognized as significant sources of greenhouse gases (GHGs), yet the global estimations of these emissions are highly uncertain due to the limited measurements taken under optimal conditions. The diurnal variability in GHG fluxes is known to be strongly influenced by various physical and biogeochemical factors, including water temperature, wind speed, primary production, and photochemical reactions. However, our understanding of how diurnal variability in gas emission processes changes over seasons is very limited. In this study, we conducted a year-long analysis of daily changes in GHG emissions from a eutrophic reservoir in Southern Spain. Our findings revealed similar daily patterns for CO2, CH4, and N2O fluxes, with higher emissions during the day than during the night, particularly during the summer months. Additionally, the stratification period led to nighttime peaks in CH4 and N2O fluxes. Furthermore, our study also identified significant dependences between GHG emissions and various environmental factors, such as radiation, wind speed, and water temperature. These findings have significant implications for our understanding of the complex mechanisms underlying GHG emissions from reservoirs, and the challenges in accurately estimating these emissions at a global scale. In addition, our study emphasizes the significance of incorporating various time scales to evaluate the variability in future GHG measurements and models and provides important insights for developing effective mitigation strategies for these emissions.

Primary Presenter: Eva Rodriguez-Velasco, University of Granada (erodvel@ugr.es)

Authors:

Andrés Martínez-García, University of Granada  ()

Miriam García-Alguacil, University of Granada  ()

Ignacio Peralta-Maraver, University of Granada  ()

Félix Picazo, University of Granada  ()

Rodrigo J. Gonçalves, University of Granada  ()

Cintia L. Ramón, University of Granada  ()

Rafael Morales-Baquero, University of Granada  ()

Francisco J. Rueda, University of Granada  ()

Isabel Reche, University of Granada  ()