Total ozone trends at three northern high-latitude stations

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