Reasons and patterns of spatio-temporal variability of methane emission from the Mozhaysk reservoir in summer period

¹ Moscow State University, Faculty of Geography, Hydrology Department, Moscow, Russia
² Institute of Atmosphere Physics Russian Academy of Science, Moscow, Russia
³ Institute of Water Problems Russian Academy of Science, Moscow, Russia

^* Corresponding author: lomson620@mail.ru

Abstract

Anthropogenic reservoirs are not only sources of clean energy, flow regulators, recreational and food resources, but also sources of greenhouse gases such as methane. The studies presented in this work, done on a well-studied low-flowing valley reservoir mainly in the summer, when the greatest variability of methane fluxes was observe. Depending on synoptic conditions, the temporal variability of methane fluxes varies greatly. Methane fluxes increase during the summer period and huge methane emissions observed before the autumn mixing stage. Emissions can occur during the destruction of temperature stratification, as a result of stormy weather. With such emissions, methane fluxes into the atmosphere can reach about 20 mgC*m^-2*d^-1, which is higher than the emission during convection. Revealing the patterns of spatio-temporal distribution of methane fluxes will help to determine the contribution of water bodies (in particular reservoirs) to the total methane budget of the atmosphere more accurately.