Impact of microphysics scheme complexity on the propagation of initial perturbations

This paper evaluates the impact of microphysical scheme complexity on the propagation of the perturbations in initial conditions for warm-season convections over the central United States. The Weather Research and Forecasting Model (WRF), in conjunction with four schemes of the Morrison microphysics parameterization with varying complexity, was used to simulate convective cases using grids nested to 5-km horizontal grid spacing.

Results indicate that, on average, the four schemes show similar perturbation evolution in amplitude and spatial pattern during the first 2 h. After that, the simplified schemes introduce significant error in amplitude and spatial pattern. The simplest (liquid only) and most complex schemes show almost the same growth rate of initial perturbations with different amplitudes during 6-h forecast, suggesting that the simplest scheme does not reduce the nonlinearity in the most complex scheme.