The development of parameterizations comprises the whole spectrum of
cloud and precipitation related processes as condensation, collision-coalescence
of drops as well as riming (s. Fig.).
The common basis of these investigations are
the spectral balance equations for the size distribution functions of corresponding
hydrometeor types. By means of moment equations and assumptions on the
structure of the size distribution functions parameterization are derived where the
(numerical) solutions of the exact kinetic equations serve as a reference. The parameterizations are occasionally extended and improved.
The latest parameterization is based on the two-moment scheme of Seifert & Beheng (2006a,b) which recently has been extended by introducing a hail class. That scheme is implemented in experimental versions of LM, MM5 and WRF.
A comparison of results obtained by applying, on one hand, the parameterization an, on the other hand, a microphysics module relying on spectral-kinetic equations is given in Seifert et al. (2006).
The parameterisations are used in projects funded by the German Science Foundation (DFG)
in the priority program ‘’Quantitative precipitation forecast’’ and the project ‘’ANTISTORM’’ funded by EC.