Interpreting airplane measurements with the help of a 3D model with detailed (bin) microphysics
A three-dimensional model with detailed (bin) microphysics is used to reproduce aircraft microphysical measurements and thus to provide explanations for the observations. The simulated case is a deep convective cloud which develops a large anvil around 10 to 14km height and is described in Heymsfield et al. (2005). This case is of interest as numerous measurements of the liquid and ice phase, temperature and vertical winds are available. The updraft core of the thunderstorm can be divided into two regions with very different characteristics. The first one with strong vertical velocities is entirely glaciated but surprisingly has a rather high temperature as compared to the environment. The second part of the updraft contains liquid water but the vertical winds are moderate and the temperature is colder than in the glaciated portion of the core. The model couples the dynamics of Clark and Hall (1991) with the DEtailed SCAvenging Model (Flossmann et al., 1985; Leroy et al., 2006). The microphysical package follows the evolution of the wet aerosol particles, drop and ice crystals spectra each with 39 bins. With this model called DESCAM 3D, we are able to simulate a realistic cloud with features very similar to the observations. The observed updraft core seems to be in fact a mixture of several ascending areas existing at different altitudes and with different microphysical and dynamical histories. Additionally, we investigated the role of atmospheric pollution on the precipitation formation. Currently, we use DESCAM 3D to study the importance of the ice phase and the atmospheric pollution level for precipitation events over the Cévennes-Vivarais region.
HyMeX – Hydrological cycle in the Mediterranean Experiment 2010-2020