Some field experiments of aerosols had been carried out over the arid and semi-arid regions in China over the past 30 years,but there were little learning of the semi-arid region of Loess Plateau.Using Version 2.0 Level 2.0 dataset from the AERONET(Aerosol Robotic Network)Lanzhou_city site,the aerosol optical properties during dusty and non-dusty periods in winter and spring when air pollution frequently occured most frequently were demonstrated.A comparison of the same parameters between Lanzhou and Beijing for spring was also analyzed.Some new information was gained concerning aerosol optical properties over the semi-arid region of Loess Plateau.The results show that the aerosol properties measured during dusty and non-dusty periods are significantly different at Lanzhou,particularly in spring,and also different from those at Beijing.
A regional climate model coupled with an aerosol model is employed to numerically simulate the direct climate effects of the anthropogenic aerosol emitted in South Asia and China in the East Asian summer monsoon during1988 to 2009.Based on the data of the numerical simulation,composite analysis and correlation analysis are used to make diagnostic study of climate dynamics.Results show that the month of maximum emission of the mean column burden of the anthropogenic aerosol in the main emission areas of South Asia is opposite in phase to that in China.Summer is the season of maximum emission amount in China,but the emission amounts are more in South Asia in spring and winter.On the whole,the mean column burden of the anthropogenic aerosol in China is relatively high compared with that in South Asia.The trend of distribution of aerosol is SW-NE in China,and Sichuan Basin is the emission center of aerosol.The effect of negative short wave radiative forcing alters the gradient of pressure between land and sea,weakening the development of East Asian summer monsoon over the northern part of Yangtze-Huaihe River Basin.We also discuss the feedback effect of East-Asian summer monsoon which is changed by the anthropogenic aerosol on the concentration and distribution of aerosol in China.
