Simulation Of Distribution Of Temporal And Spatial Variation Of PM_2.5 Over China And The Globe

Atmospheric abundances of aerosols have increased since the preindustrial period due to anthropogenic activities.The effects of aerosol on climate change, eitherthrough its optical properties or by changing the properties of clouds,have drawn more and more attention of domestic and foreign researchers.It is very difficult to assess the impact of aerosols on the climate by measurements,Therefore, we simulated the temporal and spatial distribution of the variation of PM2.5, anthropogenic and natural aerosols column burdens over the globe and surface concentrations over China for four periods during 1850-2050 and discussed the contributions of anthropogenic and natural aerosols to the variation of PM2.5 by using an coupled model from the National Climate Center of the China Meteorological Administration (NCC/CMA),called BCC_AGCM2.0.1_CUACE /Aero. The major conclusions are as follows:(1) To the globe, anthropogenic aerosols increase mainly in the eastern of North America, Europe and eastern of China during 1850-1980. During 1980-2010, there are significant reduction centers in Europe and eastern of North America, while in the east of Asia, South of Asia, Southeast of Asia and Central Africa, anthropogenic aerosols increase in various degree, anthropogenic aerosols reduce in Europe, eastern of North America and Asia in different degree both in 2010-2030 and 2030-2050 period. Whereas, the variation of natural aerosols occur around desert areas in all periods and decrease almost all over the world both in the last two periods. The temporal and spatial distribution of the variation of PM2.5 column burdens depend on the variation of anthropogenic and natural aerosols.(2) In the east of China, anthropogenic aerosols increase both in 1850-1980 and 1980-2010 periods with the variation more remarkable in spring and summer. In the north of China, natural aerosols decrease during 1850-1980 period while increase in 1980-2010 period, which also vary more remarkably in spring and summer. During 2010-2030 and 2030-2050 periods, anthropogenic aerosols reduce in the east of China in different degree in all RCPs, and remaine to be more remarkable in spring and summer.Natural aerosols decrease both in 2010-2030 and 2030-2050 periods in the north of China.(3) The contributions of anthropogenic aerosols to the variation of PM2.5 surface concentrations in 1850-1980 and 1980-2010 periods in China is 56% and 21% respectively. Though the contributions of anthropogenic aerosols reduce it doesn’t mean that the global mean variation of anthropogenic aerosols surface concentrations in 1980-2010 period are less than that in 1850-1980 period, but more instead. The global mean reduction of PM2.5 surface concentration is 2.55 μg m3 during 2010-2030 period with the contribution of anthropogenic aerosols is 28%. The anthropogenic aerosols decrease continuously during 2030-2050 and it’s contribution to the variation of PM2.5 increase(34%).