Detecting Methane Emissions from Space Over India: Analysis Using EMIT and Sentinel-5P TROPOMI Datasets

Abstract

Methane (CH₄) is a potent greenhouse gas and the second highest anthropogenic emissions are recorded from CH₄ on Earth. Considering its high global warming potential, the monitoring of source locations is inadvertent. The paper presented here is the first attempt (to the best of our knowledge) to comprehensively analyse the methane emissions over multiple Indian locations using satellite data. It outlays a brief background of methane emission sensors and studies carried out worldwide for estimation of the GHG. It further enumerates the potential of Earth Surface Mineral Dust Source Investigation (EMIT) and TROPOspheric Monitoring Instrument (TROPOMI) in highlighting the potential point sources of methane emissions and its concentration/emission flux in India. 17 unique plumes were identified using EMIT in the states of Maharashtra (06), Rajasthan (04), Punjab (02), Gujarat (03) and Assam (02). Gujarat, Surat, Assam Uttar Pradesh and Haryana using TROPOMI were also studied. The hotspots showcase emission sources from solid waste landfill sites, sewage treatment plants, wetlands/marshy agriculture, city sewage outlets, oil and gas fields, oil refinery and textile industry. It was observed that EMIT can effectively be used for point source identification, monitoring and enhancement while TROPOMI is best suited for regional level methane monitoring. A sewage outlet plume in Maharashtra produced the maximum emission of 6202.9 ± 691.94 kg/hr followed by solid waste (SW) sites located in Pirana Landfill, Ahmedabad and Khajod Landfill, Surat in Gujarat. Methane monitoring is an important step towards mitigating enormous methane emissions and anomalous methane sources.