Contrasting LWC Vertical Profiles in Convection-Cloud Chamber Simulations: The Impact of Boundary Relative Humidity and Chamber Geometry

Utilizing babyEULAG, a simplified serial incarnation of a 3D non-hydrostatic anelastic Eulerian–semi-Lagrangian framework, this study investigates cloud microphysical responses to variations in geometry and boundary conditions of a convection cloud chamber within turbulent environments. Unlike the findings from previous model simulations on the Pi Cloud Chamber (a benchmark convetion cloud chamber), our simulations reveal a notable vertical variation of liquid water content (LWC) within the cloud chamber. These vertical LWC profiles are found to be predominantly influenced by relative humidity (RH) condition at the cloud chamber boundaries and the aspect ratio of the cloud chamber. Specifically, for saturated boundary conditions (RH=100%) and the cloud chamber geometry where the horizontal scale is twice the height scale (e.g., horizontal scale = 4 m, height = 2 m; aspect ratio = 0.5), the simulated LWC remains constant with altitude within the cloud chamber. However, when these conditions are altered (undersaturated boundary conditions and aspect ratio > 0.5), the simulated LWC shows an increasing trend with altitude. These findings advance our understanding of the complex interplay between turbulent environments, cloud chamber geometry, and boundary conditions in influencing cloud microphysics. More details will be discussed at the meeting.