Modelling mixed-phase clouds with large-eddy model UCLALES-SALSA

• Main Authors: Ahola, Jaakko, Korhonen, Hannele, Tonttila, Juha, Romakkaniemi, Sami, Kokkola, Harri, Raatikainen, Tomi
• Format: Text
• Language: English
• Published: 2020
• Subjects: Arctic
• Online Access: https://doi.org/10.5194/acp-2019-1182; https://www.atmos-chem-phys-discuss.net/acp-2019-1182/

The large-eddy model UCLALES-SALSA, with exceptionally detailed aerosol description for both aerosol number and chemical composition, has been extended for ice and mixed-phase clouds. Comparison to a previous mixed-phase cloud model intercomparison study confirmed the accuracy of newly implemented ice microphysics. Further simulation with a heterogeneous ice nucleation scheme, where also ice nucleating particles (INP) are a prognostic variable, captured the typical layered structure of Arctic mid-altitude mixed-phase cloud: a liquid layer near cloud top and ice within and below the liquid layer. In addition, the simulation showed realistic freezing rate of droplets within the vertical cloud structure. The represented detailed sectional ice microphysics with prognostic aerosols is crucially important in reproducing mixed-phase clouds.