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 ΔCO₂/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 ΔCO₂/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 ΔCO₂/ΔCO are due to representativeness and limited GOSAT data.