Toward anthropogenic combustion emission constraints from space-based analysis of urban CO₂/CO sensitivity

We explore the value of multispectral CO retrievals from NASA/Terra Measurement of Pollution In The Troposphere (MOPITT v5), along with Atmospheric CO₂ Observations from Space (ACOSv2.9) CO₂ retrievals from the Japan Aerospace Exploration Agency Greenhouse Gases Observing Satellite (GOSAT), for characterizing emissions from anthropogenic combustion. We use these satellite retrievals to analyze observed CO₂/CO enhancement ratios (ΔCO₂/ΔCO) over megacities. Since CO is coemitted with CO₂ in anthropogenic combustion, the observed ΔCO ₂/ΔCO characterizes the general trend in combustion activity. Our analyses show patterns in ΔCO₂/ΔCO that correspond well with the developed/developing status of megacities, and ΔCO ₂/ΔCO that agree well with available literature and emission inventories to approximately 20%. Comparisons with ΔCO₂/ ΔCO derived from Total Carbon Column Observing Network measurements show similar agreement, where some of the differences in observed ΔCO ₂/ΔCO are due to representativeness and limited GOSAT data. Our results imply potential constraints in anthropogenic combustion from GOSAT/MOPITT, particularly in augmenting our carbon monitoring systems.