Abstract:
A new scheme of non-inductive thunderstorm electrification is developed, imbedded in the bulk microphysical scheme of RAMS v.6.0. The charge separation mechanisms use the rime accretion rate (RAR) approach (Brooks et al., 1997) and are based on the laboratory experiments of Takahashi (1978) and Saunders and colleagues (Saunders et al., 1991). A new type of hybrid scheme is tested, based on the assumption that the laboratory experiments of Saunders et al. (1991) (one-chamber) represent the charging in regions with weak mixing, while the experiments of Takahashi (1978) (two-chambers) represent the charging in regions with strong mixing. Numerical simulations of a typical thundercloud (CCOPE, 19 July 1981) indicate that the proposed hybrid scheme is capable to reproduce the basic charge structure of the storm in general agreement with observations.