Variability and Trends of Total Column Ozone and the Vertical Distribution of Ozone Over the Coastal Region of East Antarctica

Abstract

Antarctic springtime ozone reduction is spatially heterogeneous, making it essential to examine local and vertical ozone changes. However, the long‐term total column ozone (TCO) and vertical ozone structure changes in the coastal region of East Antarctica remain uncertain. This study investigates the TCO variability and vertical distribution of ozone, based on Zhongshan TCO observations (1993–2024), Davis ozonesondes (2003–2024), complemented by satellite and reanalysis data sets (SBUV, ERA5, MERRA2, and MSR2) from 1980 to 2024. TCO at stations is significantly correlated with the Antarctic regional (60°–90°S) mean (R > 0.8) and most effectively reflects the TCO variations over the coastal sector of East Antarctica (about 61°–79°S, 34°–120°E; R > 0.9) from August to December. A positive TCO trend from September to December has emerged since 2003 at Zhongshan, although persistent ozone deficits since 2020 have partially offset this upward tendency. At Davis, springtime ozone deficit occurs mainly within 165–30 hPa. In 2019, unusually high column ozone (187.81 Dobson units (DU)) in this layer coincided with sudden stratospheric warming. Since 2003, September column ozone (165–30 hPa) has exhibited an upward inclination of 0.80 ± 0.75 DU/yr, and September ozone mixing ratio deficit rates from 2018 to 2022 were lower than in 2013–2017. However, ozone deficit after mid‐September state has intensified (0.86 ± 0.62 DU/yr), highlighting the role of late‐spring reduction. This study offers a complete view of the long‐term temporal and vertical variations in ozone over the coastal region of East Antarctica and provides additional insights and evidence for springtime Antarctic ozone layer recovery.