Contrasting Impacts of Dust Ice-Nucleating Particles on the Evolution and Radiative Effects of Mixed-Phase and Ice Clouds

Abstract. The effect of aerosols acting as ice-nucleating particles (INPs) remains one of the least understood processes in aerosol–cloud–climate interactions. Mineral dust can serve as INPs in both mixed-phase and ice clouds, yet few studies have simultaneously considered dust INPs in both cloud types, limiting our understanding of their impacts on clouds and radiation. Here, we develop an improved INP parameterization in WRF-Chem that explicitly represents dust INPs in both cloud types, incorporating both non-size-resolved and size-resolved INP parameterizations. Model evaluation against ground-based and satellite observations shows good agreement with the observed spatiotemporal variations of surface PM₁₀, dust INPs, liquid water path (LWP), and ice water path (IWP) over East Asia. Simulations for spring 2018 reveal that dust INPs in mixed-phase clouds accelerate the Wegener–Bergeron–Findeisen (WBF) process, increasing IWP by 2.3 % and decreasing LWP by 3.3 %, thereby reducing cloud albedo and producing a warming of 0.20 W m⁻². In ice clouds, dust INPs enhance heterogeneous nucleation, increase ice crystal number concentrations, and reduce their effective radius. Sedimenting ice crystals from ice clouds further intensify the WBF process in mixed-phase clouds, ultimately yielding a stronger warming of 3.56 W m⁻². Differences among INP parameterizations are comparable to those between simulations with and without INPs, whereas the size-resolved scheme may more reasonably represent the spatial variability of dust INP effects. This study highlights the distinct roles of dust INPs in mixed-phase and ice clouds from the microphysical perspective and advances our understanding of aerosol–cloud–climate interactions.