Abstract
Satellite retrieval capabilities for detecting methane (CH
4
) diffuse and point sources have increased drastically over the last decade. These observations are playing an important role in atmospheric inversion systems to optimize emissions from anthropogenic and natural sources. A critical component of atmospheric inverse modelling is the prior estimate of CH
4
emissions, which impact both the magnitude of posterior emissions and the allocation between sectors, including wetland emissions. Here we incorporate point source retrievals from GHGSat to update prior emission estimate for fossil fuels. We then evaluate the effect on posterior emission using the Integrated Methane Inversion for the Western Siberian Lowlands. The updated GHGSat-informed fossil prior is highly uncertain but suggests the possibility of a reduction in wetland CH
4
flux. The approach demonstrates the potential impact of large point sources, that are typically not accounted for in bottom-up emission inventories. Due to modelling approaches adjusting anthropogenic and natural sources at the state vector level, the relative proportions of these sectors in the prior are critical for interpreting regional methane budgets and the effect of climate change on wetland emissions.