Since the beginning of the industrial revolution, the atmospheric concentration of carbon dioxide (CO
2) has increased by nearly 41%, and the Methane (CH
4) concentration has increased more than double. CH
4 is the second most important greenhouse gas, following CO
2. Emissions, extrapolated from measurements of actual gas flux from wetlands, vary from place to place, even within the same wetland. This high variability makes large-scale estimates difficult and means that average emissions levels include a large degree of estimated uncertainty. The SCIAMACHY instrument on the European Space Agency satellite ENVISAT measured greenhouse gases in the troposphere and stratosphere. In this study, the CH
4 source area is extracted by estimating the emission as the difference between CH
4 concentration in time series observed by SCIAMACHY and the background concentrations of CH
4. Missing data of CH
4 concentration by cloud are interpolated both spatially and temporally. It is assumed that CH
4 concentration is negligible over ocean and that the CH
4 concentration over the ocean is due to the advection of CH
4 from the land. The background concentration of CH
4 on the land was defined as CH
4 concentration over the ocean in the same latitude. The estimated CH
4 emissions from the land exhibited the source of CH
4 are not only in paddy fields but also in broadleaf evergreen area in South America and Central Africa.
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