The Models-3 Community Multi-scale Air Quality modeling system (CMAQ) coupled with the Regional Atmospheric Modeling System (RAMS) is used to analyze the dynamics of Elemental Carbon (EC) and Organic Carbon (OC) in East Asia during April 2001. As an emission for CMAQ, we use the anthropogenic and biomass burning emissions for NO_X, CO, NMVOC, SO₂, NH₃, EC and OC taken from the emission inventory reported by Streets et al. (2003). In addition, biogenic NMVOC emission taken from Guenther et al. (1995) are also included.
Comparison of model results with observations shows that the model reproduce thefundamental features of the observed concentrations of EC and OC over the East China Sea and the Japan Sea. The model demonstrates that EC and OC concentrations increase in up/midstream area of Yangtze River in China, and OC concentration increases also in the northern Indochina. The OC particles lifted in northern Indochina where the wind is convergent form a large-scale pronounced aerosol layer around 25°N in East Asia. Simulations with and without biomass burning emissions are conducted to quantify the impacts of biomass burning on EC and OC, and those monthly averaged values were 20% for EC, 38% for OC at surface, and 31% for EC and 46% for OC at 2, 800 m height. Model analysis shows that the primary, secondary biogenic, and secondary anthropogenic OC account for 83%, 12%, and 6% of OC at surface over East Asia, respectively, and also at 2, 800 m height, the ratio is almost the same as at surface.

View full abstract

We statistically analyzed the relationship between annual mean concentration and upper 2% excluded highest daily mean concentration of suspended particulate matter (SPM) in Tokyo metropolitan area. Environmental quality standard of SPM concentration in Japan is defined as 100μg/m³ by upper 2% excluded daily mean concentration, and we found that the annual mean concentration equivalent to the environmental standard (C_eq) has been changing remarkably from 1990 to today. We found the similar changes in other regions in Japan in 1990's. Further, we found that C_eq of NO₂ and SO₂ also have been rising in southern Kanto region in 1990's.

View full abstract