Towards Monitoring Coal Mine Methane Emissions using TROPOMI Satellite Observations

Methane (CH₄) is the second most important greenhouse gas after CO₂. Methane trapped in coal reservoirs is either extracted as coal mine methane (CMM) or vented as ventilation air methane as it presents a safety hazard. The EDGAR v4.3.2 emission inventory estimates fugitive emissions of CMM to be about 13% of the global anthropogenic methane budget. However, there are significant uncertainties to this number and the associated mitigation potential as coal mining practices and conditions can vary from country to country. This study targets the detection and quantification of CH₄ emissions from coal mines by combining a new spatially resolved high resolution bottom-up emission inventory with TROPOMI CH₄ observations. The TROPOMI instrument, onboard Sentinal-5P satellite launched in October 2017, provides daily global coverage of atmospheric CH₄ concentrations at ~7 × 7 km² on-ground resolution and has unprecedented capabilities to detect CH₄ emissions from space. We aim to quantify and characterize the localized CH₄ emissions from coal mines and reduce the uncertainty of the bottom-up estimates. As a case study, we (re)construct the coal mine CH₄ emission inventory over India, the 3^rd ranking coal producer, by following TIER-II/III level approach, and spatial allocation using the exact location of the mine. The spatially resolved CH₄ emissions will be used to identify potentially high CH₄ emitting mines, which then can be analyzed using TROPOMI data. The results of this study will be presented and compared to other available estimates. We also intend to validate our bottom-up approach for some well-monitored mines in the US and Europe.