Estimation of methane emissions from wetlands and most extreme fires in Western Siberia based on MACC / CAMS and GFED data

Abstract

Methane is an important greenhouse gas, and its atmospheric concentration has nearly tripled since pre-industrial times. This paper presents estimates of the strength of two primary sources of methane emissions in Western Siberia: wetlands emissions (WEs) and methane emissions from biomass burning (BBEs). The atmospheric circulation data used are from ECMWF Era-Interim, BBE – GFED (Global Fire Emissions Database) and CAMS GFAS (Global Fire Assimilation System), WE – MACC-III greenhouse gases inversions, v10_an. We have revealed that the highest BBE in Western Siberia (summer periods of 2005, 2006, 2007, 2010, 2011, 2012, and 2013) are accompanied by blocking in the atmosphere. We have also showed that there is a lag of 3-6 days between the beginning of the blocking and the periods of maximum BBE. Features of Rossby wave dynamics and blocking highs and ridges are examined as a possible reason for the lag. It turned out that the maximum BBE is commonly observed when a blocking high (or ridge) is shifted from Western to Eastern Siberia. The GFAS data demonstrate higher BBE than GFED (except for 2010). According to GFED, the average emission for all years is only 14.2% from WEs (the maximum emission is 35% (2012), and the minimum one, 2.2% (2007) from WEs). According to GFAS, the average emission for all years is 38.1% from WEs (the maximum emission is 127,4% (2012), and the minimum one, 6.1 (2010) % from WEs).