Impact of two boundary layer parameterization schemes and land-use data on the simulation of a heavy rainfall event

The impact of the YSU and MYJ boundary layer parameterization schemes in the WRF and two kind of land-use data with resolution of 1 km (USGS) and 500 m (MODIS) on the simulation of a heavy rainfall event from 9 to 12 May, 2014 over Qingdao were analyzed. The study shows that the experiments of YSU and MYJ could simulate the position and strength of strong rainfall regions. Threat score (TS) for MYJ was 0.88 for heavy rain, and 0.65 for YSU for torrential rain. Using MODIS data increases the TS for torrential rain by 6.2% compared to using USGS data, but still easily causes false prediction for heavy rain Experiments. YSU, MYJ and MODIS reproduce the variations of near surface temperature and wind direction. The simulation accuracy for temperature before rainfall is higher than that after the beginning of rainfall in the experiment of YSU. But for the situation of MYJ, the opposite is true. Using MODIS data predicts too high near surface temperatures on the coastal stations. Compared to the simulation from USGS, MODIS improved simulation accuracy in the field of near surface wind speed and wind direction. In general, the simulation accuracy for variables over inland stations was better than that on coastal stations. YSU is better than MYJ and MODIS is better than USGS.