Total Ozone Column Changes over Northeast China: Trends and Variability Analysis

Based on the Multi-Sensor Reanalysis Version 2 dataset, this study analyzes variations in monthly mean total ozone column (TOC) over Northeast China (40–53°N, 115–135°E) during 2015–2024. The study area in winter lies in the transition zone between high polar and low subtropical TOC in East Asian mid-latitudes. Key results indicate that the TOC over Northeast China is consistently higher than the zonal mean TOC of the same latitude band and seasonal cycle demonstrates TOC maximum (minimum) in February (August), one month (two months) earlier than for the Northern Hemisphere midlatitudes. The important role of Brewer–Dobson circulation and quasi-stationary wave (QSW) structure in the TOC distribution over Northeast China is confirmed by the 10-year climatology for January–March. The QSW pattern is characterized by the TOC decrease from the northeastern (~415 DU) to southwestern (~330 DU) parts of the region. The strongest positive (negative) correlations approaching r = 0.9 (r = –0.8) exist between TOC and ozone concentration (temperature) at 50 hPa and 100 hPa, as well as at the surface. These findings can be applied to analyze the ozone observations and stratosphere–surface couplings in the Northeast China region.