Enhancement of coalescence due to droplet inertia in turbulent clouds

摘要: The EMPM (Explicit Mixing Parcel Model) predicts the evolving in-cloud variability of temperature and water vapor mixing ratio due to entrainment finite-rate turbulent using a 1D representation rising cloudy parcel (Krueger et al. 1997). formulation allows model resolve fine-scale down smallest scales (about 1 mm). calculates growth thousands individual cloud droplets based on each droplet’s local environment (Su 1998). In EMPM, advection fluid is implemented by rearranging cells. Each permutation represents an eddy, called “triplet map.” This implementation triplet map captures flow processes as small eddy (Kolmogorov microscale), but response turbulence has important features at droplet radius. Namely, motion relative less than Kolmogorov microscale induces clustering that estimated increase collision rates significantly. We have developed (Kerstein Krueger 2006), implemented, tested 3D for this effect. also detection algorithm so we can simulate collisions coalescence between finite-inertia particles. Once map, along with stochastic coalescence, are in will be able investigate roles mixing, inertial effects, ultragiant nuclei play warm rain initiation cumulus clouds.