Advance in spectroscopic measurements of key atmosperic radicals and their applications in simulation chamber and field campaign

Chemically reactive atmospheric radicals and their precursors species (such as HO₂, NO₃, HONO, H2CO, etc.) play a crucial role in the atmospheric chemistry processes. Reliable and real-time assessment of the concentration change of such reactive species in the atmosphere is essential for understanding the oxidation capacity of the atmosphere, which might have a severe impact on air pollution models, prediction of tropospheric chemical processes, regional air quality and global climate change, and political decisions related to emission control strategies. Contrary to long-lived species (such as greenhouse gases), fast, interference-free, accurate, and precise in situ monitoring of such strongly reactive species represents a real challenge due to their very high reactivity resulting in short lifetimes (down to seconds), ultralow concentrations ranging from ppbv (10⁻⁹) to ppqv (10⁻¹⁵), and due to the complex reaction networks they participate in.

In this presentation, we will overview our recent progress in the development of spectroscopic measurement technique for optical monitoring of radicals and their precursors, including : (1) novel technique development for lab investigation; (2) intercomparison of different methods in simulation chamber and in real-world field campaign; as well as intercompaison through modeling; (3) applications to field campaigns and chamber studies.

Acknowledgments

This work is partially supported by the French national research agency (ANR) under the Labex CaPPA (ANR-10-LABX-005), ANR MULTIPAS, ANR MABCaM, ANR ICAR-HO2 and PIA SEAM contracts; the PHC-ORCHID project; the EU-INTERREG SAFESIDE project; the EU H2020-ATMOS project (Marie Skłodowska-Curie grant agreement No 872081), and the regional CPER ECRIN, CPER-IRENE, CPER-CLIMIBIO programs.

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