Seasonal, interannual and decadal variability of tropospheric ozone in the North Atlantic: comparison of UM-UKCA and remote sensing observations for 2005-2018 ...

• Main Authors: Russo, MR, Kerridge, BJ, Abraham, NL, Keeble, J, Latter, BG, Siddans, R, Weber, J, Griffiths, PT, Pyle, JA, Archibald, AT
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus GmbH 2023
• Subjects: 37 Earth Sciences; 3701 Atmospheric Sciences; 13 Climate Action; North Atlantic
• Online Access: https://dx.doi.org/10.17863/cam.90988; https://www.repository.cam.ac.uk/handle/1810/343563

Abstract. Tropospheric ozone is an important component of the Earth system as it can affect both climate and air quality. In this work, we use observed tropospheric column ozone derived from the Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) OMI-MLS, in addition to OMI ozone retrieved in discrete vertical layers, and compare it to tropospheric ozone from UM-UKCA simulations (which utilize the Unified Model, UM, coupled to UK Chemistry and Aerosol, UKCA). Our aim is to investigate recent changes (2005–2018) in tropospheric ozone in the North Atlantic region, specifically its seasonal, interannual and decadal variability, and to understand what factors are driving such changes. The model exhibits a large positive bias (greater than 5 DU or ∼ 50 %) in the tropical upper troposphere: through sensitivity experiments, time series correlation, and comparison with the Lightning Imaging Sensor and Optical Transient Detector lightning flash dataset, the model positive bias in the tropics is ...