Stable Carbon Isotope Analysis of Atmospheric Aerosols

Stable carbon isotope analysis has emerged as a powerful tool for tracing the origins, formation pathways and atmospheric processing of carbonaceous aerosol particles. By measuring the ratio of 13C to 12C (expressed as δ13C) in total carbon, organic carbon and elemental carbon fractions, researchers can distinguish between fossil-fuel, biomass-burning and biogenic sources. Advances in sample collection techniques, isotope-ratio mass spectrometry and dual-isotope approaches now allow quantification of primary versus secondary organic aerosol formation, elucidation of ageing processes and insights into long-range transport. Applications span urban pollution studies, high-altitude and polar environments, oceanic sea-spray characterisation and regional climate feedback investigations. The method supports air-quality management and climate modelling by constraining source apportionment, seasonal variability and the relative contributions of anthropogenic and natural emissions on a global scale.

Research from Nature Portfolio

Recent studies have applied dual-pool isotope models to marine aerosols, revealing two distinct carbon pools: an aged dissolved organic matter (DOM) reservoir with a relatively invariant δ13C signal around –20‰, and a fresher particulate organic matter (POM) pool exhibiting more depleted values down to –28‰. This framework explains organic-matter enrichment in sea spray, linking trophic-level dynamics and colloidal-enrichment mechanisms to observed isotope fractionation and underlining the role of marine aerosols in climate-aerosol-cloud feedback loops.

Stable Carbon Isotope Analysis of Atmospheric Aerosols publication trend

The graph below shows the total number of articles in stable carbon isotope analysis of atmospheric aerosols across all publications each year (not limited to Nature Index journals).

Technical terms

δ13C: The deviation in the 13C/12C ratio of a sample relative to a standard, reported in per mille (‰), used to infer carbon source signatures.

PM2.5: Particulate matter with aerodynamic diameters below 2.5 µm, a key metric for fine aerosol sampling in air-quality studies.

Organic aerosol: Atmospheric particles composed primarily of organic compounds, encompassing both directly emitted (primary) and chemically formed (secondary) fractions.

Secondary organic aerosol (SOA): Organic aerosol produced in the atmosphere through oxidation of volatile organic compounds, often exhibiting distinct isotope fractionation.

References

1. Measurement report: Chemical components and 13C and 15N isotope ratios of fine aerosols over Tianjin, North China: year-round observations. Atmospheric Chemistry and Physics (2023).
2. Non‐Fossil Origin Explains the Large Seasonal Variation of Highly Processed Organic Aerosol in the Northeastern Tibetan Plateau (3,200 m a.s.l.). Geophysical Research Letters (2023).
3. Stable isotopes measurements reveal dual carbon pools contributing to organic matter enrichment in marine aerosol. Scientific Reports (2016).