EGU25-13109, updated on 15 Mar 2025
https://doi.org/10.5194/egusphere-egu25-13109
EGU General Assembly 2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
Overview of the Third Cabauw Intercomparison of UV-Vis DOAS instruments (CINDI-3)
Michel Van Roozendael, Arnoud Apituley, Karin Kreher, Diego Alves Gouveia, Alexander Cede, Udo Friess, Martina M. Friedrich, Elena Spinei Lind, Alexis Merlaud, Ankie Piters, Andreas Richter, Frederik Tack, Thomas Wagner, and Steffen Ziegler
Michel Van Roozendael et al.
  • Royal Belgian Institute for Space Aeronomy (BIRA-IASB), Atmospheric Reactive Gases, Brussels, Belgium (michelv@oma.be)

The third Cabauw Intercomparison of UV-Vis DOAS Instruments (CINDI-3) took place from May 21st to the 24th of June 2024 at the Cabauw Experimental Site for Atmospheric Research (CESAR), a semi-rural observational facility managed by the Dutch Meteorological Institute close to the cities of Rotterdam and Utrecht in the Netherlands. Its main objective was to intercompare UV-Vis MAX-DOAS instrument types targeting nitrogen dioxide, ozone, aerosols and several other reactive gases such as formaldehyde, glyoxal and BrO, with the aim to assess their performance under a range of observational conditions, and to progress towards the understanding of the measurement technique through community effort. The stationary UV-Vis observations were complemented with a range of additional measurements including ozone and aerosol lidars, NO2 and ozone sondes, long-path DOAS and in-situ instruments. Furthermore, mobile instruments were deployed around Cabauw, De Bilt and Rotterdam during selected days with favourable weather conditions using cars and bikes as well as a small research aircraft, to provide a more complete picture of the distribution of pollutants from the industrial and urbanised area around Rotterdam.

CINDI-3 was organised under the umbrella of NDACC and the European Research Infrastructure ACTRIS with additional support from ESA and NASA. In total, over 100 researchers from 16 countries participated to the field deployment. In this presentation, we provide an overview of the main on-site activities and we highlight first results of the post-campaign data evaluation with a focus on the ACTRIS/NDACC semi-blind intercomparison exercise and activities under way in various working groups addressing calibration, trace gas and aerosol vertical profiling, spectral retrieval improvements, and the joint exploitation of mobile and airborne measurements.

How to cite: Van Roozendael, M., Apituley, A., Kreher, K., Alves Gouveia, D., Cede, A., Friess, U., Friedrich, M. M., Spinei Lind, E., Merlaud, A., Piters, A., Richter, A., Tack, F., Wagner, T., and Ziegler, S.: Overview of the Third Cabauw Intercomparison of UV-Vis DOAS instruments (CINDI-3), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13109, https://doi.org/10.5194/egusphere-egu25-13109, 2025.