Radiative forcing due to dust aerosol over east Asia-north Pacific region during spring, 2001

An optical model accounting for the East Asian dust is proposed as a result of theory calculation and composition analysis of the aerosol samples collected in China desert during the international project, "Studies on the Origin and Transport of Aeolian Dust and its Effects on Climate (ADEC)". Study indicates that dust aerosols emitting from China deserts have smaller imaginary parts of refractive indices, therefore absorb less and scatter more solar radiation than the most dust optical models published so far. Furthermore, the forward fraction of scattering is less and the backscattering is stronger than those of the other models. The seasonal averaged radiative forcing in spring, 2001 over east Asia-north Pacific region is simulated employing the new dust optical model. The net forcing at the top of atmosphere (TOA) is estimated as -0.943 W · m^-2 for regional and seasonal mean, with shortwave and longwave contributions of -1.700 and 0.759 W · m^-2, respectively. The surface net forcing is calculated to be -5.445 W · m^-2, and made up of shortwave component of -6.250 W · m ^-2 and longwave component of +0.759 W · m^-2. The distributions of TOA and surface net forcing over this region are also analyzed in this study.