Temporal-spatial distribution of tropospheric NO2 in China using OMI NO2 column measurements

Observations of tropospheric column densities of NO₂ obtained from the satellite instruments OMI for the period of 2005 to 2010 are used to derive average monthly and seasonal variations over China. The obtained results indicate that NO₂ has an imbalanced spatial distribution with the highest level in North China, Yangtze Rive Delta region and Pearl River Delta region. The seasonal pattern of the NO₂ concentration shows a difference between the east and west in China. In the eastern part of China, an expected winter maximum in seasonal cycle is found. In the western part this cycle shows a NO₂ maximum in summer time. The NO₂ concentration shows a large growth over eastern China during the same period. Correlation analysis reveals that column densities of NO₂ is the most closely correlated with coal consumption per unit area and population density.