Aerosol optical, chemical and physical properties at Gosan, Korea during Asian dust and pollution episodes in 2001

In order to understand the influence of dust and anthropogenic pollution aerosols on regional climate in East Asia. we analyzed the aerosol optical, chemical and physical properties for two cases with high aerosol loading and assessed the radiative forcing of these cases. The 1st case study is a heavy dust episode (DE) in April (during ACE-Asia) 2001 and the 2nd case is a regional-scale pollution event in November 2001. The Angstrom exponent (Angstrom) for DE was. VIS from sunphotometer measurements. The mean single scattering albedo (550 nm) at the surface reported during the pollution episode (PE, 0.88) was lower than that of DE (0.91). The concentrations of organic (OC) and elemental carbon (EC) measured during the PE were about 90% and 30% higher than DE. The aerosol mass scattering efficency (alpha(s)) of PE is a factor of about 2 higher than that of the DE. The difference in the mass absorption efficiency (z(a)) of EC during DE and PE is small and within the measurement uncertainty. The diurnally averaged aerosol radiative forcing efficiency (DeltaDFE, W m(-2) tau(-1)) during DE is similar to results of other studies at Gosan. (C) 2004 Elsevier Ltd. All rights reserved.