Measurements of stable isotope ratios in atmospheric gases and aerosols help us to identify and quantify chemical, physical and biological processes that affect our atmosphere. Measurement of isotopic composition have become a widely used tool to investigate the sources and sinks of a large amount of important atmospheric gases, e.g. carbon dioxide, carbon monoxide, methane, hydrogen, nitrous oxide, sulphur dioxide, ozone and volatile organic compounds, including halogenated ones. In recent years, this tool has been extended and applied also to various components of atmospheric aerosols, for example nitrate, sulfate and organic aerosols.
Moreover, the discovery of non-mass dependent isotope fractionation processes and the development of clumped isotope measurement techniques have added additional isotope dimensions to the toolbox of the isotope community.

The session is open to all contributions that use isotope techniques in the investigation of atmospheric trace gases, including field studies, laboratory and simulation experiments, novel sampling or analytical techniques, and modelling activities.

Topics addressed in this session include:
- Stable isotope ratios in atmospheric gases and aerosols
- Kinetic isotope effects
- Non-mass dependent isotopic fractionation and related isotope anomalies
- Poly-substituted isotopocules ("clumped isotopes")
- Stable isotope ratios in the past, present and future atmosphere