9314465 Wang The main objective of this study is to understand the growth process of ice particles in clouds and precipitation. The study will investigate the growth of large particles where the particles perform oscillating motions in air. The PIs will study both the diffusional growth and riming of ice particles in two contexts, i.e., from both the individual particle and cloud dynamical points of view. To achieve the first goal, they will numerically solve the unsteady Navier-Stokes equations for flow past ice particles of various shapes and then use the flow fields so obtained to determine the diffusional growth and riming by solving the convective diffusion equations of vapor and the equation of motion of supercooled droplets. To achieve the second goal, they will parameterize the results obtained and incorporate them in a cloud dynamical model. Finally, they will participate in the WISP94 experiment to collect real ice samples and use their models to interpret the observation. ***