| In recent years, the concentration of aerosols in the atmosphere increased as affected by human activities which triggered a series of problems in the atmosphere, such as reduced atmospheric visibility which is inconvenience for people’s travel, the impact on human health, as well as resulting in areas of extreme precipitation, cooling and other extreme. Thus, the impact of aerosols on climate is getting worse. The clouds and precipitation in the climate system is playing an important role, thus increasing the impact of clouds and precipitation of aerosol research, it is already an important direction for climate research.Aerosols mainly through indirect effects influence clouds and precipitation. Satellite remote sensing data has the advantage of a wide coverage, high repetition rate, and is true and reliable. Other observational data and numerical simulations can not get these. So satellite remote sensing data to study aerosol effects on clouds and precipitation in China were used. Researchers showed that the role of clouds and aerosols on precipitation may be in the strongest in summer, so this article studied the interaction between aerosol and cloud and precipitation respectively in August 2013 and summer harvest season in June 2014. The interaction between aerosol and cloud, precipitation in the removal of atmospheric conditions were studied. Principal component analysis for the NCEP atmospheric parameters, CERES data of aerosol parameters, and cloud parameters, a total of 24 participated in the study were mainly used, and combined with TRMM precipitation data, through the correlation analysis between the principal components and precipitation. In June 2014 the summer harvest season, for example, this research compared before and after straw combustion analysis in the summer harvest period. Firstly data from MODIS aerosol, fine particles and fire point were analyzed in the summer harvest period, and aerosol optical thickness and distribution of the hot spot before and after the straw combustion were also analyzed, then in the specific region (South North China and Yangtze River Delta region) the use of small particles reveal the main causes of pollution during the summer harvest. To further study, track pollution transport model analysis of a particular region on behalf of the city were used, and ultimately concluded. And finally it analyzed in a specific area, the impact of aerosols on cloud parameters.The conclusions are as follows:(1) Aerosol optical depth values in August 2013 in China are distributed about 0.006 to 1. There are two high-value areas, respectively North China and the northwest ofChina. North China is mainly affected by the development of industry, and the other high-value area is mainly influenced by the Northwest surface of the desert. Cloud optical thickness has larger value in the south, and the value of north except the Northeast is smaller. Distribution of aerosol optical depth and cloud droplet effective radius, has the opposite trend for the central region is small, and the northwest (except desert areas) and the Northeast is large. The distribution of precipitation mainly decreases from the southeast to the northwest, so there is a great relationship with the southeast monsoon.(2) Through the principal component analysis, we finally get six main components. Wherein the fourth principal component explains when aerosols increases, cloud optical thickness, cloud cover decreases, indicating that the aerosol growth is not conducive to the formation of aerosols thick cloud, thus affecting the precipitation. The fifth principal component descripts that when aerosols increases, cloud optical thickness increases, which is reflecting the first indirect effect of aerosols, and the first effect in eastern China is most obvious.(3) Based on the role of aerosol and cloud parameters in the main component, available aerosols is mainly in the fifth main component, and cloud is mainly in the second and fifth components. Through correlation coefficient between the fifth component and precipitation, we derived that with the growth of aerosols, precipitation decreases.(4) Through the comparative analysis, we found that high value areas are located in southern Hebei, Shandong, Henan, Jiangsu, Anhui and Shanghai. In June 2014 the average aerosol optical thickness is much higher than in North China in 2014, and in some areas such as Jiangsu and Anhui provinces, even up to twice. June as the main summer harvest period, we used the fire point to divide its time to give the three time periods fire point profiles and aerosol optical thickness distribution with respect to the time period. We can get 1-5 June straw preliminary emission which is relatively small aerosol optical thickness; 6-14 June period for the combustion of straw concentrate, aerosol optical thickness is largest; 15-22 centralized straw combustion end stage, and aerosol optical thickness values for the previous stage is smaller. We can preliminary get that June high pollution was caused by burning straw.(5) Through the hot spot distribution and corresponding aerosol distribution in the study area, we chose two interesting areas to obtain fine particles distribution maps. The concentration of fine particles is most below 0.8 in the straw concentrated pre-combustion stage; two research areas of high value than the fine particles increases, even beyond 0.8 in the straw concentrate combustion stage. Straw burning concentrated late in the study area in the case of the thickness of two particles coexist. Pollution in June was mainly fine particles caused by anthropogenic activities. Through backward trajectories of HYSPLIT model in June 6 to 14, the pollutants of in urban cities in the two of the study area are densely distributed through the hot spot areas. The conclusion is that straw burning centralized in the summer harvest period resulted high pollution in the North China Plain.(6) Through the before and after straw concentrate burning, all with the aerosol optical thickness value increases in the value of the two study areas, and the reaction of cloud liquid water path and cloud optical thickness in the two regions is different. It appears to reduce in the north, but increases in the Yangtze river delta region. The results show that indirect effect in the Yangtze river delta is obvious but in north China aerosol effect is still more complicated. |
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