Anthropogenic and dust aerosol components estimated by satellite data over the China’s seas

The method of estimating anthropogenic and dust aerosol components directly from satellite data is given.The method uses the relationship between the fine mode fraction and the aerosol optical thickness in MODIS data to respectively compute anthropogenic and dust aerosoloptical thicknesses in China for the first time.The result shows that the result obtained with the method is good over the China's seas,and the anthropogenic and dustoptical thicknesses have marked season variation and spatial distribution.In different seasons,the anthropog enic aerosol optical thickness is the largest in spring and summer and it is the smallest in fall and winter.Nevert heless,the dust aerosol optical thickness is the largest in winter and spring and it is the least in summer and fall.They show marked variation along the longitude and obvious variation along the latitude.In the long it udinal direction,the anthropogenic aero so loptical thickness appears to be the maximum value between 30° and 45°N and decreases northwards and southwards,which suggests that human influence is the most serious in this region.Meanwhile,the dustaerosol optical thickness appears to be the maximum value between 33° and 40°N and it is too small at other latitudes,which suggests that the region influenced by dustis limited.In the meridional direction,the anthropogenic aeroso loptical thickness has excellent relationship with the distance far from the coast.The anthropog enic aeroso loptical thickness reaches the maximum value round 120°E which is near the coast and it gradually decreases with the longitude increasing,which is caused by anthropog enic influence.On the other hand,as big particles,dustaerosol is difficult to be transported to remote region,so dustaerosol only affects a small meridional area.The dust aerosol optical thickness appears to be the maximum value between 120° and 123°E and it is too small at other long itudes.