CLARIFICATION OF MECHANISMS OF METHANE EMISSION IN LAKE ABASHIRI

The 4th IPCC report demonstrated that sea level rise is from 0.18 to 0.59 m and the increase in temperature is from 1.1 to 6.4 degrees. Methane is considered one of the most influential gasses on climate change, and the previous studies demonstrated that about one-fourth of methane emission is given from lakes and wetlands. However, the mechanisms of the occurrence of methane is not clarified enough. Therefore, this study aims to develop the transportation model of methane from a lake by applying 3D numerical model. As a result, it is revealed that methane emission from bottom layer, methane decomposition of an aerobic microbe and methane decomposition of an anaerobic environment are key factors for the emission of methane in a lake.