[A-AS04] [EE] Global Carbon Cycle Observation and Analysis

[AAS04-03] Monitoring anthropogenic carbon dioxide and methane emission at regional scale using GOSAT observations

*rajesh janardanan achari¹、Shamil S Maksyutov¹、Tomohiro Oda²、Makoto Saito¹、Akihiko Ito¹、Johannes W Kaiser³、Alexander Ganshin⁴、Tsuneo Matsunaga¹、Yukio Yoshida¹、Tatsuya Yokota¹ (1.National Institute for Environmental Studies, Tsukuba, Japan、2.USRA/GSFC NASA, Greenbelt, MD, USA、3.Max Plank Institute for Chemistry, Mainz, Germany、4.Central Aerological Observatory, Dolgoprudny, Russia)

キーワード：anthropogenic emission, greenhouse gases, emission monitoring

Carbon dioxide (CO₂) and methane (CH₄) are the most important greenhouse gases in terms of radiative forcing. Anthropogenic activities such as combustion of fossil fuel (for CO₂) and gas leakage, animal agriculture, rice cultivation and landfill emissions (CH₄), are considered major sources of their emission. Emission data usually depend on national emission reports, which are seldom evaluated independently. Here we present results of a statistical method of comparing anomalies in global atmospheric CO₂ and CH₄ (2009-2014) fields due to anthropogenic activities, using GOSAT observations of column-average dry air mole fractions (XCO₂ and XCH₄) with atmospheric transport model simulations using high-resolution emission inventories. The CO₂ and CH₄ concentration enhancement due to anthropogenic activities, are estimated with the transport model for all GOSAT observations using high-resolution emission inventories (ODIAC and EDGAR respectively). Based on these values, anthropogenic greenhouse gas abundance is calculated using GOSAT observations as anomalies from clean background observations. These anomalies are binned and analyzed for continental scale regions and countries. For CO₂, we have found global and regional linear relationships between model and observed anomalies especially for Eurasia and North America. The analysis for East Asian region showed a systematic bias (around 15%) that is comparable in magnitude to the reported uncertainties in emission inventories in that region. In the case of CH₄, we found a good match between inventory-based estimates and GOSAT observations for continental regions. The inventory-based estimates over North American region is biased upward (around 35%) which is in agreement with recent reports. The results indicate the potential utility of GOSAT observations in monitoring reported anthropogenic emissions over different regions of varying spatial scales.