Comparative analysis of simulations on a heavy snow event in Liaoning province using different cloud microphysical parameterization schemes

A heavy snow event that occurred in Liaoning province on 4 March 2007 was simulated using four different microphysical parameterization schemes included in the WRFv3.9.1 model (Lin, WSM6, Thompson, WDM6). The capability of the model for precipitation simulation was evaluated based on observations collected at 61 national weather stations. The precipitation phase and spatial distribution of hydrometeors were compared between simulations using different cloud microphysical parameterization schemes. The result shows that the reflectivity simulated by the four schemes is consistent with the CloudSat satellite observations, the echoes simulated by the Thompson scheme are higher and extend further north than the simulations by the other three schemes, which are all located at around 8 km altitude. The precipitation area is slightly different between simulations by the four schemes, and the simulated rainfall area by all these schemes is located further north than the observations. From the perspective of subjective evaluation and objective skill scores, the WSM6 scheme performs best according to the TS score and the precipitation cell location. The boundary between rain and snow areas and its southward moving are well simulated by the WSM6, Lin and WDM6 schemes, but the transition time from rain to snow simulated by the Thompson scheme is later than observation. All of these schemes can simulate rain drops at lower levels, but the rain water content simulated by the WDM6 is more than that simulated by the other three schemes. More snow and less graupel are found in the result of the Thompson scheme, while the graupels are distributed at higher levels and extend widely in the simulation by the Lin scheme. Both the WSM6 and WDM6 schemes simulate less graupels and simulated cloud ice particles are located in lower levels. Different distributions of hydrometeors simulated by different microphysics schemes lead to different simulations of precipitation and precipitation phase.