Supplementary material for paper "Operational chemical weather forecasting with the ECCC online Regional Air Quality Deterministic Prediction System version 023 (RAQDPS023) - Part 2: Multi-year prospective and retrospective performance evaluation" by

Description of Contents: The large PDF file entitled “Part2_Supplementary_Material_22August2025.pdf” contains the Supplementary Material for the paper by Moran et al. (2025). Extensive use has been made of tags and links in this PDF file to make movement around the document by section, table, or figure number easier. The zip file contains 15 oversize tables that did not easily fit into the Supplementary Material PDF file. The other three PDF files contain collages of plots extracted from the supplement of monthly time series for related sulfur, oxidized nitrogen, and reduced nitrogen chemical species. These files are intended to support the interpretation and discussion of model predictions and behaviour in the paper. Citation: Moran, M.D., Lupu, A., Savic-Jovcic, V., Zhang, J., Zheng, Q., Boutzis, E.I., Mashayekhi, R., Stroud, C.A., Ménard, S., Chen, J., Menelaou, K., Munoz-Alpizar, R., Kornic, D., and Manseau, P.M.: Operational chemical weather forecasting with the ECCC online Regional Air Quality Deterministic Prediction System version 023 (RAQDPS023) – Part 2: Multi-year prospective and retrospective performance evaluation, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2025-4324, 2025. Related Zenodo Links: Modelling system source code: https://zenodo.org/records/13952893 2013-2016 predicted gridded concentration and acidic deposition output package: https://doi.org/10.5281/zenodo.16970403 AQ measurement data sets, model-measurement pairs, and performance evaluation tables: https://doi.org/10.5281/zenodo.16944371 Keywords: Performance evaluation, ozone forecasts, PM2.5 forecasts, chemical weather prediction, RAQDPS, GEM‑MACH, retrospective simulations, hindcasts Contact Information: [email protected]; [email protected]