CNR Ozone Sounding Merged ( COSM ) Dataset From Existing Global Archives

ABSTRACT

This article presents a unified ozonesonde dataset, COSM (National Research Council of Italy (CNR) Ozone Sounding Merged), integrating observations from the SHADOZ (Southern Hemisphere ADditional OZonesondes), NDACC (Network for the Detection of Atmospheric Composition Change) and WOUDC (World Ozone and Ultraviolet Radiation Data Centre) archives. The dataset spans the period 1978–2024, with actual observations covering this entire range, and contains approximately 101,500 vertical ozone profiles collected at 124 stations worldwide. The COSM dataset was constructed through a harmonization process and the application of systematic quality control procedures designed to detect and correct issues such as unit inconsistencies, implausible values and incomplete metadata, while accounting for differences in instrumentation, reporting formats and vertical resolution across networks. The COSM dataset provides a structured, quality‐assessed and well‐documented archive of global ozonesonde observations. Compared with the original archives, the COSM dataset improves spatial and temporal coverage, facilitating consistent use in long‐term studies of ozone variability and trends. A representativeness assessment, based on satellite‐derived ozone profiles, confirms that stations with the longest and most continuous records provide meaningful spatial coverage, particularly in tropical and mid‐latitude regions. In addition to ozone, the COSM dataset also includes typical thermodynamic variables such as temperature, pressure and relative humidity. To our knowledge, this is the first unified and openly available collection of ozonesonde records combining SHADOZ, NDACC and WOUDC. The dataset is relevant for a wide range of applications, including climate and chemistry model evaluation, satellite product validation, and data assimilation into reanalysis. By consolidating heterogeneous archives into a single resource, it provides the scientific community with a comprehensive, quality‐assessed and accessible dataset, which is openly distributed via Zenodo.