Radiative Process and Sulfate Direct Effect in FGOALS-s2

Abstract

The radiative process in the Spectral Atmospheric General Circulation Model of the National Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics/Institute of Atmospheric Physics (LASG/IAP) known as SAMIL, which is the atmospheric component of the Flexible Global Ocean–Atmosphere–Land System (FGOALS-s2), is briefly described in this study. The treatment of main aerosol optical properties is also discussed, particularly for sulfate aerosols. Our results show that the updated sulfate optical properties in FGOALS-s2 can effectively process the sulfate hydroscopic effect, which shows a significant improvement over the previous model version. The global annual mean sulfate direct radiative forcing (DRF) relative to the pre-industrial era is calculated with SAMIL to be −0.37 Wm⁻² in all-sky condition, which is comparable to results of previous research. Moreover, regional meteorological fields are shown to significantly influence sulfate radiative forcing, particularly in East Asia. Further studies will be focused on improving the parameterization of direct and indirect climate effects due to anthropogenic aerosols.