Accuracy of the Wind Speed Profile in the Lower PBL as Simulated by the WRF Model

Abstract

Wind resource assessment for coastal areas requires accurate wind speed simulation using a mesoscale model. Our previous study found that the annual mean wind speed simulated by the advanced research Weather Research and Forecasting (WRF-ARW) model has a remarkable positive bias in the lower part of the planetary boundary layer (PBL). This result was obtained from a comparison with wind profiler measurements at Mihama, which is an observation station of the WInd profiler Network and Data Acquisition System (WINDAS) operated by the Japan Meteorological Agency (JMA). In this study, we examine whether such a positive bias can be seen at other WINDAS stations from a comparison of the WRF-simulated wind speed profile using the Mellor-Yamada-Janjic (MYJ) PBL scheme with wind profiler measurements at ten WINDAS stations. The results show that the positive bias is found at all stations, and, moreover, that the positive bias is unlikely to be caused by either error in wind profiler measurement or the objective analysis data input into WRF. In addition, we compare the wind speed profiles simulated by WRF with seven different PBL schemes for a month. The result shows that the positive bias cannot be simply reduced by using other PBL schemes.