Analysis Of Temporal And Spatial Characteristics Of Aerosol Over Land In 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 atmospheric, Aerosol characterization has been paid more and more attention.Using AOT (Aerosol Optical Thickness) and FMF (Aerosol Fine Mode Fraction) of MODIS from2000to2010, space and time changes of AOT and FMF in our country are analyzed in this paper. Then five types of aerosol, marine type, dust type, urban/industry type, continental type and biomass type, are classified using AOT and FMF, and the details of the five kinds of aerosol are described. At last, the paper based on the conditions of the aerosol generated, combined with the ground cover, dust sand influence, population distribution, gross domestic product, discusses the reasons of the aerosol distribution characteristics.The analysis results are as followed:(1) High AOT in our country mainly concentrated in some areas of North, East, and central China and Sichuan Basin, as well as desert region of Northwest China, while low AOT-means were distributed in Northeast and Southwest of China and Qingzang Plateau. Through the data analysis of the interannual-changes from2000to2010, the growth areas of AOT were mainly distributed in South of Northeast, West and Central of Inner Mongolia, the desert marginals, and Southwest China. And the reduced areas of AOT are including North of Northeast China and the Southwest mountainous areas of China. The High-value season of AOT season-changes are mainly distributed in spring and summer in most areas of China. Generally speaking, the AOT’s values changes smaller in autumn and winter. Large seasonal variation areas mainly include Tianjin, Shandong, Henan, Jiangsu.(2) The High-value areas of FMF are mainly located in Northeast and Southwest of China, while Low-value areas are mainly distributed in West and Central of Inner Mongolia, Gansu, Ningxia, Xinjiang, Qinghai, Xizang. From the2000to2010’s data analysis, FMF exists growth trends in East and Center of China. The reduced regions of FMF are mainly distributed in Northeast China, Inner Mongolia, Northwest of Xinjiang, Fujian, Yunnan, South of Guizhou and Guangxi, Guangdong. The high-value areas of FMF are generally distributed in summer, however, FMF’s value is smaller in spring, autumn and winter. Large seasons-changes areas of FMF are mainly including in Northeast China, North of Inner Mongolia, Hebei, Tianjin, Chongqing, East of Sichuan, North of Guizhou, and most areas of Central and East China(3) The marine type aerosol is mainly located in some regions of Northeast China and Southwest China in autumn and in North of China in spring and summer. The dust type aerosol is generally distributed in some regions of eastern-central China in winter. Urban/industrial type aerosol is generally distributed in east China, while continental type areas mainly consists the northern regions of Northeast China, the western regions of Central China and the east regions of Southwest China. Biomass type is mainly distributed in Shandong, Jiangsu, southeast part of Sichuan, and the junction of Henan and Anhui. For seasonal variation of aerosol, each type of aerosol has a significant seasonal variation.(4) In the areas with greatly undulate terrain and high vegetation cover, AOT and FMF is small, and the aerosol type is mainly marine type. Vegetation seasonal changes affect the seasonal variation of the FMF, the correlation is above0.8, while the seasonal changes have little effect on AOT’s seasonal variation. AOT and dust weather have high correlation in the dust prone areas than in the dust less prone areas. Population density, gross domestic product and coal consumption have an effect on atmosphere aerosol, especially, population density and economic development.