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.

Higher Apparent Gas Transfer Velocities for CO Compared to CH in Small Lakes.

Large greenhouse gas emissions occur via the release of carbon dioxide (CO) and methane (CH) from the surface layer of lakes. Such emissions are modeled from the air-water gas concentration gradient and the gas transfer velocity (). The links between and the physical properties of the gas and water have led to the development of methods to convert between gases through Schmidt number normalization.

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.