Observational Evaluation of WRF Planetary Boundary Layer Schemes for Sea–Land Breeze Circulation in Coastal Ningbo, China

Due to variations in surface characteristics, terrain, and geographical conditions, the performance of planetary boundary layer (PBL) schemes in the Weather Research and Forecasting (WRF) model can vary substantially among coastal regions. In this study, 11 PBL schemes were evaluated for a representative sea–land breeze (SLB) event over Ningbo, China. The simulated 2 m temperature, 10 m wind speed, and 10 m wind direction were compared with observations from three surface meteorological stations, while radiosonde observations from Hangzhou were used to assess the simulated vertical temperature and relative humidity structures. For the 2 m temperature, YSU and SH produced the lowest nominal RMSE values of 1.588 and 1.595 °C, respectively, followed by GBM, UW, ACM2, and MYJ. However, paired moving-block bootstrap analysis showed that the RMSE differences between YSU and SH, GBM, UW, ACM2, and MYJ were not statistically distinguishable at the 95% confidence level. For 10 m winds, UW produced the lowest wind speed RMSE, BouLac showed the smallest absolute wind speed bias and the highest correlation coefficient, and MYNN2.5 yielded the lowest circular mean absolute error for the wind direction. The simulations also showed scheme-dependent differences in sea breeze evolution and vertical atmospheric structure. Overall, no single PBL scheme consistently outperformed the others across all evaluated variables and metrics. These results highlight the importance of evaluating PBL schemes using multiple observational constraints when simulating sea–land breeze circulation in complex coastal environments.