Minor impacts of rain on methane flux from hemiboreal, boreal, and subarctic lakes.

Methane (CH) emissions (F) from northern freshwater lakes are not only significant but also highly variable in time and one driver variable suggested to be important is precipitation. Rain can have various, potentially large effects on F across multiple time frames, and verifying the impact of rain on lake F is key to understand both contemporary flux regulation, and to predict future F related to possible changes in frequency and intensity of rainfall from climate change. The main objective of this study was to assess the short-term impact of typically occurring rain events with different intensity on F from various lake types located in hemiboreal, boreal, and subarctic Sweden.

Diel variability of methane emissions from lakes.

Lakes are considered the second largest natural source of atmospheric methane (CH). However, current estimates are still uncertain and do not account for diel variability of CH emissions. In this study, we performed high-resolution measurements of CH flux from several lakes, using an automated and sensor-based flux measurement approach (in total 4,580 measurements), and demonstrated a clear and consistent diel lake CH flux pattern during stratification and mixing periods.

Aquatic methane dynamics in a human-impacted river-floodplain of the Danube.

River-floodplain systems are characterized by changing hydrological connectivity and variability of resources delivered to floodplain water bodies. Although the importance of hydrological events has been recognized, the effect of flooding on CH concentrations and emissions from European, human-impacted river-floodplains is largely unknown. This study evaluates aquatic concentrations and emissions of CH from a highly modified, yet partly restored river-floodplain system of the Danube near Vienna (Austria).