Methane in the Danube Delta: the importance of spatial patterns and diel cycles for atmospheric emission estimates

A comprehensive study of methane emissions from the Danube Delta reveals significant spatial and diel variability, challenging previous assumptions about wetland greenhouse gas contributions. The research found that channels within the delta exhibit the highest methane concentrations, with seasonal and water flow dynamics further influencing emission patterns. Notably, diel cycles in lakes and channels showed extreme variations, with concentrations fluctuating by an order of magnitude, suggesting daily vertical stratification driven by macrophytes. This phenomenon introduces a substantial uncertainty factor of 4.5 in emission estimates. The study highlights the critical need for high-resolution, spatio-temporal data to accurately model methane emissions from complex wetland systems like the Danube Delta.

Canning, A., Wehrli, B., & Körtzinger, A. (2021). Methane in the Danube Delta: the importance of spatial patterns and diel cycles for atmospheric emission estimates. Biogeosciences, 18(12), 3961–3979. https://doi.org/10.5194/bg-18-3961-2021