Abstract:

Nitrogen dioxide(NO2)plays a key role in the chemistry of the atmosphere，and NO2 pollution is getting worse with the development of economy.Using OMI,the results of monthly averaged tropospheric NO2 change trends of Beijing,Shanghai,Guangzhou,Wuhan and Xi’an from October 2004 to July 2009 were obtained,and their characteristics of these changes were analyzed.The monthly averaged OMI tropospheric NO2 column over these five cities were compared with the monthly averaged surface mass concentration of NO2,which were calculated according to the Air Pollution Index of NO2 for these five cities from January 2007 to December 2008.The result showed that these two sets of data had the same change trend.Furthermore,the OMI was also used to gain the distribution map of annual average NO2 concentration of the downtown in these five cities from 2005 to 2008.It was found that the downtown NO2 concentration was much higher than rural areas,and this formed the turbid island effect in the urban climate.These were closely related to developed city traffic,high population activity and the urban heat island circulation.In addition,annual averaged GOME tropospheric NO2 were compared with the number of vehicles of the five cities in the 10year period from 1999 to 2008.These analysis results showed that high correlation coefficients were obtained between the vehicle exhaust emissions and NO2 pollution.