Observational Evidence of Large Contribution from Primary Sources for Carbon Monoxide in the South Asian Outflow

Dasari, S and Andersson, A and Popa, ME and Röckmann, T and Holmstrand, H and Budhavant, K and Gustafsson, O (2021) Observational Evidence of Large Contribution from Primary Sources for Carbon Monoxide in the South Asian Outflow. In: Environmental Science and Technology, 56 (1). pp. 165-174.

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Abstract

South Asian air is among the most polluted in the world, causing premature death of millions and asserting a strong perturbation of the regional climate. A central component is carbon monoxide (CO), which is a key modulator of the oxidizing capacity of the atmosphere and a potent indirect greenhouse gas. While CO concentrations are declining elsewhere, South Asia exhibits an increasing trend for unresolved reasons. In this paper, we use dual-isotope (δ13C and δ18O) fingerprinting of CO intercepted in the South Asian outflow to constrain the relative contributions from primary and secondary CO sources. Results show that combustion-derived primary sources dominate the wintertime continental CO fingerprint (fprimary ∼ 79 ± 4%), significantly higher than the global estimate (fprimary ∼ 55 ± 5%). Satellite-based inventory estimates match isotope-constrained fprimary-CO, suggesting observational convergence in source characterization and a prospect for model–observation reconciliation. This “ground-truthing” emphasizes the pressing need to mitigate incomplete combustion activities for climate/air quality benefits in South Asia.

Item Type:	Journal Article
Publication:	Environmental Science and Technology
Publisher:	American Chemical Society
Additional Information:	The copyright for this article belongs to the Authors.
Keywords:	Air pollution; Atmospheric chemistry; Carbon monoxide; Combustion; Greenhouse gases, Central component; Incomplete combustion; Model-observation reconciliation; Oxidizing capacity; Premature death; Primary sources; Regional climate; Source apportionment; South Asia; Strong perturbations, Isotopes, carbon 13; carbon monoxide; oxygen 18; carbon monoxide, air quality; atmospheric pollution; carbon monoxide; outflow; pollutant source; pollution exposure; satellite altimetry, air quality; Article; climate; combustion; isotope analysis; South Asia; South Asian; air pollutant; air pollution; environmental monitoring; particulate matter, South Asia, Air Pollutants; Air Pollution; Carbon Monoxide; Environmental Monitoring; Particulate Matter
Department/Centre:	Division of Mechanical Sciences > Centre for Atmospheric & Oceanic Sciences
Date Deposited:	30 Jun 2022 09:47
Last Modified:	30 Jun 2022 09:47
URI:	https://eprints.iisc.ac.in/id/eprint/74082

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