模式分辨率对东北地区近地层风场预报性能的影响
Effect of Model Horizontal Resolution on the Surface Wind Speed Forecast in the Northeast China
中文摘要：
应用WRF模式，以ECMWF全球环流预报场为模式背景场，对辽宁和吉林区域进行了4个典型月的10和3.33km分辨率的预报试验，并基于两个省的47座测风塔同期观测资料，对预报结果进行了常规统计检验、关键区间检验，以及预报误差的分解，探讨不同分辨率对东北地区近地层风场预报性能的影响。结果表明：1）模式水平分辨率对风速频率曲线的影响不大，但在辽宁的预报效果优于吉林；2）全风速段检验结果表明70m高度预报性能优于10m高度；3）模式分辨率的变化对均方根误差分解后各项的贡献率影响不大，但存在模式分辨率越高，位相差略微增加，系统差和幅度差的贡献略微降低的现象；4）分辨率的变化对不同风机工况的预测准确性有一定影响，在冬、春季表现为分辨率越高，无功工况下的预报准确性越高；而在夏、秋季分辨率越高满发工况准确性越高；5）不论哪个季节，分辨率的提高均导致发电工况下的TS评分降低，均方根误差增大，相对误差增大。可见在我国东北地区，并非模式分辨率越高风速预报准确性越高。
中文关键词：
ECMWF，水平分辨率，近地层，风速，预报
KeyWords：
ECMWF, WRF model, horizontal resolution, surface layer, wind speed
Abstract：
Experimental studies of surface wind forecasts were carried out by employing the WRF model at two different resolutions of 10 km and 3.33 km on the background field of global circulation forecasts from ECMWF for 4 typical months in Liaoning-Jilin provinces. The conventional statistical verification, key wind speed segment verification, and different decomposition of forecast error were analyzed based on observation data at 47 wind towers in the two provinces during the same period. The verification results of effects of different horizontal resolutions on the forecast performance of wind speed in boundary layer were discussed in Northeast China region. The main conclusions are gotten as followings: 1) the effect of model horizontal resolution was little on the wind speed frequency, but the forecast performance was better in Liaoning province than that in Jilin; 2) The verification results of full wind speed segment show that the prediction performance at 70m height was better than that at 10m height; 3) the effect of model resolution on the RMSE after decomposition was little; but that for the phase difference was increased slightly; the system difference and amplitude difference were decreased slightly with higher resolutions; 4)The effect of different model resolutions on the forecast performances of the wind speed were little under different conditions of wind turbine generator. The forecast performances of wind speed under reactive condition were higher with a higher model resolution in winter and spring, while the forecast performance of wind speed under full load condition were higher with higher resolution in summer and autumn; 5) When the model resolution is higher, TS score was lower in the wind speed forecasts under power generation condition, the RMSE was higher and the relative error was higher in all seasons. In Northeast China, the forecast performance of wind speed was not better with higher model resolution.