Total ozone trends at three northern high-latitude stations

• Published in: Atmospheric Chemistry and Physics
• Main Authors: Bernet, Leonie, Svendby, Tove, Hansen, Georg, Orsolini, Yvan, Dahlback, Arne, Goutail, Florence, Pazmino, Andrea, Petkov, Boyan, Kylling, Arve
• Other Authors: Norwegian Institute for Air Research (NILU), Norwegian University of Science and Technology Trondheim (NTNU), Norwegian University of Science and Technology (NTNU), University of Oslo (UiO), STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institute of Polar Sciences Venezia-Mestre (CNR-ISP), National Research Council of Italy, Università degli studi "G. d'Annunzio" Chieti-Pescara Chieti-Pescara (Ud'A)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]; Arctic; Ny-Ålesund; Norway; Andøya; Climate change; Ny Ålesund
• Online Access: https://insu.hal.science/insu-04060799; https://insu.hal.science/insu-04060799/document; https://insu.hal.science/insu-04060799/file/acp-23-4165-2023.pdf; https://doi.org/10.5194/acp-23-4165-2023

International audience Afterthedecreaseofozone-depletingsubstances(ODSs)asaconsequenceoftheMontrealProtocol, it is still challenging to detect a recovery in the total column amount of ozone (total ozone) at northern high latitudes. To assess regional total ozone changes in the “ozone-recovery” period (2000–2020) at northern high latitudes, this study investigates trends from ground-based total ozone measurements at three stations in Norway (Oslo, Andøya, and Ny-Ålesund). For this purpose, we combine measurements from Brewer spectrophotome- ters, ground-based UV filter radiometers (GUVs), and a SAOZ (Système d’Analyse par Observation Zénithale) instrument. The Brewer measurements have been extended to work under cloudy conditions using the global ir- radiance (GI) technique, which is also presented in this study. We derive trends from the combined ground-based time series with the multiple linear regression model from the Long-term Ozone Trends and Uncertainties in the Stratosphere (LOTUS) project. We evaluate various predictors in the regression model and found that tropopause pressure and lower-stratospheric temperature contribute most to ozone variability at the three stations. We report significantly positive annual trends at Andøya (0.9 ± 0.7 % per decade) and Ny-Ålesund (1.5 ± 0.1 % per decade) and no significant annual trend at Oslo (0.1 ± 0.5 % per decade) but significantly positive trends in autumn at all stations. Finally we found positive but insignificant trends of around 3 % per decade in March at all three stations, which may be an indication of Arctic springtime ozone recovery. Our results contribute to a better understanding of regional total ozone trends at northern high latitudes, which is essential to assess how Arctic ozone responds to changes in ODSs and to climate change.