Exploring Multiple Constraints of Anthropogenic Pollution in Combustion Regions from Current Satellite Retrievals of Atmospheric Composition

More accurate and consistent analysis of anthropogenic pollution emissions, at scales that is relevant to air quality, energy, and environmental policy is imperative. Here, we explore observational constraints from satellite-derived measurements of atmospheric composition on bulk characteristics of anthropogenic combustion in megacities and fire regions. We focus on jointly analyzing co-emitted combustion products such as CO₂, NO₂, CO, SO₂, and aerosols from GOSAT, OCO-2, OMI, MOPITT, and MODIS retrievals, in conjunction with USEPA AQS and NASA field campaigns. Each of these constituents exhibit distinct atmospheric signatures that depend on fuel type, combustion technology, process, practices and regulatory policies. Results from three proof-of-concept studies show that distinguishable patterns and relationships between the increases in concentrations across the megacity (or enhancements) due to emissions of these constituents enable us to: a) identify trends in combustion activity and efficiency, and b) reconcile discrepancies between state- to country-based emission inventories and modeled concentrations of these constituents. For example, the trends in enhancement ratios of these species reveal combustion emission pathways for China and United States that are not captured by current emission inventories and chemical reanalyses. Analysis of their joint distributions has considerable potential utility in current and future integrated constituent data assimilation and inverse modeling activities for monitoring, verifying, and reporting emissions, particularly for regions with limited observations and limited information on local combustion processes. This work also motivates the need for continuous and preferably collocated satellite measurements of atmospheric composition, including CH₄ and CO₂, and studies related to improving the applicability and integration of these observations with ground- and aircraft- based measurements.