Atmospheric radicals (OH, HO₂, RO₂, NO₃ and halogen oxides) control the oxidation of trace gases, drive the formation of secondary pollutants such as ozone, and influence climate. Their sources, such as HCHO, HONO and ClNO₂, and their chemical fate determine how primary pollutants are transformed, so understanding them is central to addressing regional air pollution and climate change. Yet radicals remain among the hardest species to study. Their concentrations are extremely low, they react very quickly, and the reaction networks they initiate are highly complex.
This session brings together experimentalists and modellers working on radical chemistry across laboratory, chamber and field settings. We invite contributions on the development of techniques for detecting radicals, their precursors and intermediate species, and on the adaptation of instruments to ground-based, mobile, shipborne, airborne and other platforms. We also welcome work on quality assurance, including calibration procedures and inter-comparison of different techniques, as well as on model development, from new reactions and mechanisms to revised model configurations and uncertainty analysis. Finally, we encourage studies that apply radical measurements and modelling in field and chamber experiments.