Abstract:Lightninggenerated NOx (LNOx) affects the distribution of atmospheric components and is the main source of Nitrogen Oxides (NOx) in the upper troposphere. Strong optical radiation produced by lightning discharge can induce photochemical reaction. Lightning discharge promotes the vertical transportation of NOx, which causes the increases of NOx content in the upper troposphere. This study is to make the quantitative analysis of the vertical column density distribution of tropospheric NOx in China and its correlation with lightning activity, by using the measurements of the lightning density observed by the LIS sensor equipped on TRMM satellite and the vertical column density of tropospheric NO2 observed by the OMI sensor equipped on Aura satellite from 2005 to 2013 respectively. It is found that the monthly variations of lightning density and tropospheric NO2 vertical column density are almost the same on the Tibet Plateau. Both of the lightning density and the tropospheric NO2vertical column density are high in summer and low in winder on the Tibet Plateau. The tropospheric NO2 vertical column density generated by each flash is about 339 mol/flash, which is evaluated by using the data from the Tibet Plateau. Based on the result of the lightninggenerated NOx, the temporal and spatial distributions of LNOx/NOx in China are evaluated. It is found that LNOx/NOx on the Tibet Plateau is about 20% to 50% in spring and summer and less than 20% in winter. The LNOx/NOx in Sichuan Basin, Yangtze River Delta and Pearl River Delta regions is high in summer and low in winter, and generally less than 20%. The average of LNOx/NOx in China is less than 10%. The lightninggenerated NOx is the main source of NOx on the Tibet Plateau, but is not the main source of NOx in Sichuan Basin, Yangtze River Delta, and Pearl River Delta regions. The results reveal the relationship between lightning activity and NOx distribution in the troposphere over China. It is also important for understanding tropospheric NOx vertical column density and its correlation with the lightning activity.