Duann, Y.Chang, L. C.Chiu, Y.-C.Salinas, Cornelius Csar JudeDmitriev, A. V.Ratovsky, K. G.Medvedeva, I. V.Vasilyev, R.Mikhalev, A. V.Liu, J. Y.Lin, C. H.Fang, T.-W.2025-01-222025-01-222024-12-18Duann, Y., L. C. Chang, Y.-C. Chiu, C. C. J. H. Salinas, A. V. Dmitriev, K. G. Ratovsky, I. V. Medvedeva, et al. "Atomic Oxygen Ion Retrieval from 630.0 Nm Airglow during Geomagnetically Quiet Periods: A Mid-Latitude Case Study near Irkutsk". Geoscience Letters 11, no. 1 (18 December 2024): 55. https://doi.org/10.1186/s40562-024-00370-6.https://doi.org/10.1186/s40562-024-00370-6http://hdl.handle.net/11603/37371This study develops and validates three photochemical inversion models to retrieve atomic oxygen ion density ([O⁺]) profiles from 630.0 nm airglow emissions in the mid-latitude ionosphere during geomagnetically quiet period. Using passive ground-based instruments and empirical models, the models were tested and compared against electron density data from FORMOSAT-₃/COSMIC (F₃/C) and DPS-₄ digisonde at Irkutsk. Among the models, Inversion Model ₃ showed the strongest agreement with observations, particularly in capturing seasonal variations such as the June–July peak and a secondary March–April peak, which were absent in IRI-2012 predictions. These results highlight the potential of Inversion Model ₃ for accurate [O⁺] retrieval, offering a novel approach for monitoring ionospheric variability using passive photometric observations.20 pagesen-USAttribution 4.0 Internationalhttps://creativecommons.org/licenses/by/4.0/PhotochemistryAirglowRegion4 digisondeIonosphere FCOSMICDPSText