Inversion Estimates of Methane Emission in the Middle East in 2010-2017 with GOSAT Observations

Abstract

Ten years of Greenhouse gas Observing SATellite (GOSAT) observation achieves valuable retrievals for top-down methane (CH4) emissions estimates especially in regions lacking ground-based observations. This paper presents the long-term 2010-2017 trend in CH4 emissions in the Middle East countries. We use a global 0.1° × 0.1° high-resolution inverse model, NIES-TM-FLEXPART-VAR (NTFVAR) with GOSAT retrievals and surface observations. Prior fluxes contain adjusted EDGAR v4.3.2 scaled to match the country totals by national reports to the United Nations Framework Convention on Climate Change (UNFCCC), augmented by biomass burning emissions from Global Fire Assimilation System (GFASv1.2) and wetlands emissions from Vegetation Integrative Simulator for Trace Gases (VISIT) model. The result shows the total annual CH4 emission of 23.54 Tg CH4 yr −1 in the Middle East with more than 95% emissions from anthropogenic sources, and there is no statistically significant emissions trend from 2010 to 2017.