Rebuild The Long-term Time Series Of Black Carbon And Inorganic Water-soluble Ions Aerosol Spectrum Over South China

In our study, the size distribution of EC and inorganic water-soluble ions and aerosol spectrum over SouthChina and Northern South China Sea have be discussed based on Size-segregated aerosol samples collectedover South China and Northern South China Sea during1988–2010period, which including city sites, ruralsites, coastal sites and island. Thus, the variation of the pollutants over South China between earlystage(1988-1990) and late stage(2008-2010) were discussed. Then we designed the origin of all samplingsites, selected valuable statistical methods to rebuild the long term time series of BC over South China andNorthern South China Sea, which were provided the input parameters for the climate model assessing theregional climate and environmental change, to reduce the uncertainty of aerosol radiative forcing estimate.Through above research, we have gained some conclusions as follows:1、The concentrations of EC and inorganic water soluble ions show much differences in different sites. Theconcentration of Na+and Cl-were in the order of island>coastal sites>rural sites>urban sites, while EC andother ions were in the opposition order.2、The size distribution of EC and inorganic water soluble ions show much differences in different sites anddifferent stages,figuring out that the EC and ions may come from different sources.3、The vertical size distribution of EC and inorganic water soluble ions can be divided into three categories:Trimodal pattern:(SO2-4, NO-+3and NH4); Bimodal pattern: F-, Ca2+, Mg2+, Na+, Cl-; a single peak:K+andEC.4、Rain has significantly removal effect on the aerosol particles, especially on the size bins of1.1-2.1μm.5、In the local pollution progress, the size distribution of EC concentration showed a obvious "single peak“.6、From the composition of PM10and PM2.1aerosol spectrum, we can see that the coarse particle pollutiondecreased in the late stage comparing to the early stage, while the concentration of secondary ions (SO2-4,NO-3and NH+4)and carbonaceous aerosols(EC and OC) increased.7、The aerosol spectrum showed obvious seasonal differences in different sites. In the HP Tower, theproportion of carbonaceous aerosol decrease height while other ions showed a opposition trend.8、The optical properties of aerosols concerned with the size distribution of aerosols, their compositionspectrum and relative humidity. The contribution to the light extinction of particles in the accumulationmode were the greatest.9、The concentration of BC over South China showed a downward trend from1988to2010,especially after2007,similar to the long term trend of haze days in Guangzhou.