Abstract:In this study,by using the Weather Research and Forecasting(WRF) model with five different planetary boundary layer options(no planetary boundary layer scheme,Yonsei University scheme,Mellor-Yamada-Janjic scheme,asymmetric convective version 2 scheme and medium-range forecast scheme),a rainstorm which occurred in July 2013 in the Yangtze River area was simulated.Through comparison with the observation data,the respective simulation capabilities of the five different experimental designs were evaluated.Then their simulated precipitation area,total rainfall amount,and basic meteorological elements were analyzed.The observations show that the simulated results obtained using the various schemes are different.The rain band's general trend can be accurately simulated,regardless of whether or not the PBL parameterization schemes are used,yet the simulations of the intensity and location of the rainfall center differ to some extent.The largest rainfall simulation bias occurs in the experiments performed without the planetary boundary layer scheme,while the experiments performed with the asymmetric convective version 2 and medium-range forecast schemes produce better rainfall simulations.In particular,the experiment using the Mellor-Yamada-Janjic scheme yields the best simulation results for small and large rainfall,while when coupled with the Yonsei University scheme,the model yields the highest threat score (TS) for the simulation of rainfall with various intensities.Through the analysis and comparison of various physical quantities,the following conclusions are drawn:1)Compared to the other schemes,the simulation results of the MYJ scheme are closer to the observed values;2)The MYJ scheme can simulate two water vapor transport channels:one is dominated by southwesterly wind,with strong convergence of south wind speed at the exit of the jet stream,which drives the water vapor coming from the southwest converge to the rainstorm area;while the second conveys the water vapor from east to west to ensure the local convergence of the rainstorm area;and 3)The vertical motion center and precipitation area from the MYJ and YSU schemes are similar,but the YSU-simulated rising speed is larger,thus in comparison the MYJ scheme is more reasonable.