The Advanced Radiative Transfer Modeling System (ARMS) developed in the China Meteorological Administration (CMA) has been integrated in the numerical weather prediction (NWP) system, serving national meteorological satellite series development and supporting operational satellite data assimilation. Satellite observations in the infrared (IR) and visible (VIS) bands are critical for NWP, yet they are significantly influenced by atmospheric particles. The omission of aerosol effects in the radiative transfer modeling of shortwave radiance can introduce substantial biases, particularly in heavily polluted regions and during pollution episodes. ARMS incorporates a default aerosol scheme based on GOCART, enabling the simulation of aerosol-affected radiances. To support multiple-source data from different chemistry transport models (CTMs), we further developed aerosol schemes for CAMS and GEOS-5 within ARMS, along with their corresponding optical property lookup tables. These schemes are configured align with the latest versions of these CTMs in terms of physical parameter settings and treatments in refractive indexes, hygroscopicity, and particle size distributions, etc. Monodisperse particle optical properties are calculated using Lorenz–Mie theory. Nonspherical properties for dust and sea salt are accounted for using the T-matrix method. Polydisperse optical properties are derived by assuming a lognormal distribution. The scattering phase functions are expanded in a Legendre polynomial series, and the expansion coefficients are truncated by applying the δ-M method. Mass extinction coefficient (ke), single scatter albedo (w), asymmetry parameter (g), and phase coefficients (pcoeff) are stored to enable radiative transfer modelling of aerosol scattering/absorption and satellite radiance simulation under different observation geometries. The lookup tables were evaluated using aerosol products from the CTMs outputs, and official CAMS and GEOS-5 aerosol lookup tables. Good consistency in ke was observed across wavelengths between the constructed lookup tables and the official ones, as well as in aerosol optical depth (AOD) between the recomputed and official products. The updated system was applied to radiance simulations for the Fengyun geostationary and polar-orbiting satellite series. Cases for Fengyun-3F (FY-3F) HIRAS and Fengyun-4B (FY-4B) GIIRS/AGRI demonstrate a marked positive impact on aerosol-affected radiance simulations. In heavily polluted regions, the brightness temperature (BT) bias can be reduced by 1-2 K, and reflectance simulations are improved, underscoring the importance of accurate aerosol representation for infrared and visible radiance assimilation.

ARMS; radiative transfer; aerosol; Fengyun satellites; data assimilation