Evaluation of Global Climate and Storm-Resolving Model Representations of Mixed-Phase Clouds and Their Hemispheric Contrasts

Mixed-phase clouds, in which liquid droplets and ice crystals coexist at temperatures between −38∘C and 0∘C, play a critical role in Earth’s radiation budget. In this work, we compare observations from the Advanced Very High Resolution Radiometer (AVHRR) and the Moderate Resolution Imaging Spectroradiometer (MODIS), with one global climate model, the Community Atmosphere Model version 6 – Oslo configuration (CAM6-Oslo), and three storm-resolving models: the ICOsahedral Non-hydrostatic model (ICON), the Simple Cloud-Resolving E3SM Atmosphere Model (SCREAM), and the Goddard Earth Observing System model (GEOS). Specifically, we compare mixed-phase cloud occurrence, thermodynamic partitioning, and hemispheric contrast, and introduce joint histograms of supercooled liquid fraction (SLF) and liquid effective radius (r_liq) to analyse microphysical behavior. Our results show that all models reproduce the geographic distribution of mixed-phase clouds, but differ significantly in detail. CAM6-Oslo yields the closest agreement in hemispheric SLF contrasts and SLF–r_liq relationship. Our results highlight the role of aerosol-cloud interactions and microphysics schemes in determining model performance, and demonstrate that storm-resolving models do not solve the ongoing challenge of representing mixed-phase clouds at global scales.