Stable isotopes and other novel tracers, such as carbonyl sulfide (COS) and clumped isotopes, help to identify and quantify biological, chemical and physical processes that drive Earth's biogeochemical cycling, atmospheric processes and biosphere-atmosphere exchange. Recent developments in analytical measurement techniques now offer the opportunity to investigate these tracers at unprecedented temporal and spatial resolution and precision.

This session includes contributions from field and laboratory experiments, latest instrument developments as well as theoretical and modelling activities that investigate and use the isotope composition of light elements (C, H, O, N) and their compounds as well as other novel tracers for biogeochemical and atmospheric research.

Topics addressed in this session include:

- Stable isotopes in carbon dioxide (CO2), water (H2O), methane (CH4) and nitrous oxide (N2O)
- Novel tracers and biological analogues, such as COS
- Polyisotopocules ("clumped isotopes")
- Intramolecular stable isotope distributions ("isotopomer abundances")
- Analytical, method and modelling developments
- Flux measurements
- Quantification of isotope effects
- Non-mass dependent isotopic fractionation and related isotope anomalies