Distinct Diurnal Cycle of Supercooled Water Cloud Fraction Dominated by Dust Extinction Coefficient

Cloud phase (CP) partitioning (e.g., supercooled water cloud fraction, SCF) is often misrepresented in model simulations. One of the remarkable uncertainties involves poor understanding SCF diurnal cycle due to lack observations. By using 33 months lidar observations from Cloud-Aerosol Transport System which provides top at different local times for a given grid and isotherm, this study first characterizes between 51°S 51°N. Distinct variations have been found near-global isotherms, especially −22.5°C, where ranges even reach 60%. Correlation analysis shows robust dependence on variation dust aerosol extinction coefficient instead other load indicators meteorological parameters. Given important roles radiation budget, will help us better constrain aerosol-cloud interaction simulations CP models.