Abstract
Recent anthropogenic NOx emission trends over East Asia between the years 2000 and 2012 were analyzed based on the GEOS Chem chemical transport model (CTM), tropospheric NO2 vertical column density (VCD) from four environment monitoring satellites and the REAS Ver 2.1 emission inventory. The GEOS Chem model was applied to the Asian domain with a 0.5˚×0.667˚ resolution, and the NO2 lifetime parameters were modified to have a better agreement with the observations. Analysis of the satellite NO2 VCD observations over CEC (Central East China) showed that its concentration level has been increasing at 10%/year between 2000 – 2005. The GEOS Chem simulation by the REAS emission inventory well reproduced the satellite observation trends up to the year 2008. The relationship between the NOx emission intensity and N budget components (such as NO, NO2, N2O5, HNO3 and nitrate) were examined, and our model study confirmed the high linear regression (NO2_VCD = 0.08 + 0.012×NOx_emission in 1015 moleculues/cm2 unit; R2 = 0.995 ) averaged over the CEC region. This relationship indicates that the satellite observed NO2 VCD is a very good measure for the NOx emission intensity change.
