New Global Dataset of Tropospheric Ozone over Oceans and Polar Regions

Kanaya et al. (2025) present the first comprehensive dataset of tropospheric ozone over the global oceans and polar regions, integrating 77 ship/buoy and 48 aircraft campaigns conducted between 1977 and 2022 across the 0–5000 m altitude range. Compiled through worldwide collaboration within the atmospheric research community, the dataset unifies decades of measurements under consistent quality control. Each observation is accompanied by backward-trajectory analyses that quantify how long sampled air masses were isolated from land, allowing users to extract data representative of marine conditions (e.g., ≥72 h isolation). The refined subset reveals pronounced daytime ozone decreases (11–16%) in the tropical marine boundary layer, while near-zero depletions—common in the Arctic—are rare, suggesting different controlling mechanisms. The dataset is openly available as CSV files at https://doi.org/10.17596/0004044. Its use in the forthcoming paper "Tropospheric Ozone Assessment Report II: Ozone Distribution and Variability in the Oceanic and Polar Regions" under International Global Atmospheric Chemistry (IGAC) is anticipated, and further SOLAS-relevant applications are strongly encouraged.

Reference: Kanaya, Y., Sommariva, R., Saiz-Lopez, A., et al. (2025). Observational ozone datasets over the global oceans and polar regions (version 2024). Earth Syst. Sci. Data, 17, 4901-4932. https://doi.org/10.5194/essd-17-4901-2025