Analysis Of Aerosol Types And Sources In The Typical Pollution Region Of China Based On MODIS Product

Atmospheric aerosol plays an important role in the earth’s radiation balance, and has a very important impact on human life and global climate change. As one of the important factors affecting the atmosphere, Aerosol characterization has been paid more and more attention.Using AOD (Aerosol Optical Depth) and FMF (Aerosol Fine Mode Fraction) of MODIS from2003to2012, space and time variations of AOD and FMF in our east country are analyzed in this paper. Then six types of aerosol, clean marine type, desert dust type, urban/industry type, continental type, biomass burning type and mix type, are classified using AOD-FMF method, and the seasonal variations of the six types of aerosol are described, and the backward trajectory of the5AOD high value area based on8years GDAS Data has been discussed in different seasons. At last, a continuous air pollution event in Jiangsu and Anhui provinces had been analyzed based on satellite remote sensing and field observations.The analysis results are as followed:(1) The High-value areas of AOD in our country mainly concentrated in five areas of North China, The Yangtze River Delta, Central China, Sichuan Basin and The Pearl River Delta, while low AOD-means were distributed in Northeast and Southwest of China. Through the data analysis of the inter-annual variations from2003to2012, the invariant areas of AOD were mainly distributed in The Yangtze River Delta, Sichuan Basin and The Pearl River Delta, and the reduced areas of AOD are including North China and Central China areas. The High-value of AOD season-variations are mainly distributed in spring and summer in the five pollution areas of China. Generally speaking, the AOD’s values changes smaller in autumn and winter.(2) The High-value areas of FMF are mainly located in Northeast and Southwest of China, while Low-value areas are mainly distributed in Inner Mongolia and North China. Through the data analysis of the inter-annual variations from2003to2012, the reduced areas of FMF were mainly distributed in North China, and FMF exists growth trends in the other four areas. The high-value areas of FMF are generally distributed in summer and autumn, and the range of high value in autumn is smaller than summer, however, FMF’s value is smaller in spring, autumn and winter.(3) Through the data analysis of aerosol types from2003to2012. The mainly aerosol type in the Yangtze River Delta is dust type and continental type, in The Pearl River Delta is urban/industry type and continental type, in Sichuan Basin is continental type, in Central China is continental type and in North China is dust type. On the seasonal variations, except in the Pearl River Delta region and the Sichuan Basin, the main type of each of the other regions of aerosols is dust in winter and spring, the main types of summer and autumn is continental type. But the main aerosol types of the Pearl River Delta and the Sichuan Basin are urban/industrial type and continental type. Probability of urban/industrial aerosol changed little throughout the whole year in the five regions. Marine aerosol occurred mainly in the Pearl River Delta region. Biomass burning aerosol mainly occurred in summer and autumn, and mainly distribute in North China, the Yangtze River Delta region and the Central China.(4) Backward trajectory data statistics from2005to2012in the five regions showed that, there is a closely relation between the dust type aerosol and the northerly air masses. Local air mass control makes the aerosol enriched in the region, leading to the high Probability of continental and urban/industrial-type aerosol in the areas of high emissions. North China and the Central China, have much higher ratio of air mass trajectories from the north comparing to the other three regions, especially in winter and spring. While in summer, according to the proportion of the east southerly air mass increases, the dust aerosol particles decreases, and the other type aerosols increase significantly.(5) Integrated use of satellite data and ground observations, in a pollution incident showed the empty base-the foundation of two data combined with excellent properties.