Abstract: Analysis of tropospheric ozone residue (TOR) data from satellite measurements indicates an increasing trend of tropospheric ozone over the Yangtze Delta region of China. The increasing trend can be derived both from the annual mean TOR and from the monthly mean TOR except for March. During the period of 1978-2000, the increase in the annual mean TOR was 0.82 DU per decade. The study on impact of this long-term trend on the climate and atmospheric oxidizing capacity over the region should be done. Data comparison shows a significant correlation between the TOR and surface ozone data collected at the GAW Lin誥n regional background station in the Yangtze Delta region, suggesting that the observational data have regional representativeness.

Key words: tropospheric ozone, long-term trend, the Yangtze Delta