Fossil Fuel CO2 Emission Signatures Over India Captured by OCO-2 Satellite Measurements

Monitoring greenhouse gas (GHG) emissions is crucial for developing effective mitigation strategies. Recent advances in satellite remote-sensing measurements allow us to track greenhouse gas emissions globally. This study assessed ${\text{CO}}_2$ emissions from various point or local sources, particularly power plants in India, using 8 years of concurrent high-spatial resolution OCO-2 satellite measurements. A Gaussian plume (GP) model was used to evaluate the power plant emissions reported in the Carbon Brief (CB) database. In total (39 cases), 42 different power plant ${\text{CO}}_2$ emissions were assessed, with 26 of them being assessed more than once. The estimated power plant ${\text{CO}}_2$ emissions were within $\pm$ 25% of the emissions reported in the CB database in 11 out of 39 cases and within $\pm$ 50% in 18 cases. To evaluate the EDGAR and ODIAC ${\text{CO}}_2$ emission inventories in terms of missing and highly underestimated sources, we estimated the cross-sectional (CS) ${\text{CO}}_2$ emission flux for 45 cases. We identified the possible omission of power plant emissions in three cases for both inventories. Furthermore, we also showed 17 cases in which ${\text{CO}}_2$ emissions from unknown (non-power plant) sources were highly underestimated in the EDGAR and ODIAC ${\text{CO}}_2$ emission inventories. Due to the simplicity of the employed approaches and their lower computational requirements compared to other methods, they can be applied to large data sets over extended time periods. This enables the acquisition of initial emission estimates for various sources, including those that are unknown and underestimated.