Fig. 7: Seasonality of methane (CH4) dynamics in upland Yedoma thermokarst mounds.
From: Upland Yedoma taliks are an unpredicted source of atmospheric methane
a In summer, aerobic methane oxidation dominates surface soils; nonetheless, methane escapes to the atmosphere from anaerobic taliks through preferential flow paths (red dots), such as those formed along melted ice-wedge casts (red-blue dashed lines in the talik). b In winter, relatively larger seasonal methane emissions from the talik are due to a decrease in aerobic methanotrophy by freezing of surface soils. Wintertime methanogenesis in deep talik soils and barometric pressure pumping of methane from taliks also enhance winter emissions.
