Evaluation of three scale-aware planetary boundary layer schemes in WRF Model during Beijing 2022 Winter Olympics

This study employs the WRF-based RMAPS-ST numerical weather prediction model to conduct 1-km resolution simulations of the Beijing Winter Olympic Games on February 2022. An inter-comparison of the SH, the SMS and the IUM scale-aware PBL schemes is conducted. The performance of YSU as a traditional PBL scheme is also evaluated as a baseline. The investigation focuses on their ability to forecast over three distinct competition areas, Beijing (BJ), Yanqing (YQ), and Zhangjiakou (ZJK), each characterized by different terrain. The results reveal that the IUM and SMS schemes generally outperform the YSU and the SH schemes, particularly in the BJ area, where IUM exhibits the lowest root-mean-square error (RMSE) for 2-m temperature and 10-m wind speed. In YQ, with its complex topography, there are no significant discrepancies among the schemes, while SMS improves wind speed forecasts in ZJK. An abrupt nocturnal warming and a gusty wind case are chosen to further demonstrate the performance in all schemes. Results show that IUM scheme can reproduce these two cases, attributed to its stronger turbulence mixing length. These findings underscore the importance of scale-aware PBL schemes in improving high-resolution weather forecasts and diverse meteorological conditions. The IUM scheme, in particular, emerges as a promising tool for future numerical weather prediction applications.