Implications of dust minerals on radiative transfer at regional scale, using the METAL-WRF model

Abstract. Dust particles originating from desert areas of the planet have significant radiative impacts on the ground and atmospheric column, changing the energy distribution of the entire earth system, which cannot be underestimated, as dust is considered a climatic regulator. The magnitude of the dust radiative effect is dependent on the optical properties of desert dust aerosols, which in turn is regulated by the composition and mineralogical content of desert dust plumes. The mineralogical composition in atmospheric models is commonly related to the soil type at dust sources and the optical properties needed are provided by observational campaigns and dedicated measurements. In this work we upgrade the METAL-WRF model to incorporate the direct radiative impact of the minerals in dust and test the impact of the direct radiative feedback on a 2-month simulation period, namely March and April 2022, when consecutive intense dust outbursts affected the Mediterranean Basin. The simulation results were compared against Global Horizontal Irradiance data and AERONET optical properties that were measured at five sites. An improvement was observed in all sites, especially close to the sources, when the minerals and dust are treated as interacting in the radiative transfer calculations, thus improving the capabilities of METAL-WRF to simulate the chemical composition of dust particles in the atmosphere along with their contribution to radiative transfer processes.