METHANE EMISSIONS FROM THERMOKARST LAKES IN THE SOUTHERN TUNDRA OF WESTERN SIBERIA

Abstract

Lakes are an important natural source of methane – significant greenhouse gas of the modern atmosphere. Monitoring of methane emission from lakes ofnorthern territoriesis needed to update the available estimates of CH4 emission intensity into the atmosphere and to obtain multi-year series of observations. Field measurements of diffuse methane fluxes were carried out on lakes at different stages of thermokarst process located in Yamalo-Nenets Autonomous District (Western Siberia, Russia) during summer 2016 using static chamber method. Some statistical characteristics of measured fluxes were calculated (medians vary from 0.46 to 0.93 mgC-CH4∙m ∙h ), as well as annual diffuse emissions from studied lakes, which values are determined by the area of the lake’s water surface. Daily dynamics of methane fluxes were defined and approximation of fluxes with simple model was done, major factors are temperatures of lake bottom and of the surface air layer.

Keywords

• greenhouse gases
• fluxes
• methane
• freshwater ecosystems
• polar regions