相似集合预报技术在粤西风场预报中的应用

The Application of Analogue Ensemble Technique in Forecasting the Wind Field of Western Guangdong Province

利用ERA5再分析资料与常规站点观测资料,采用相似集合法(AnEn)对粤西地面风的日平均风速与日最大风速释用进行订正。结果表明:日平均风速与日最大风速订正后的准确性得到明显提高,且在地形复杂的山区也有较好的订正效果。日平均风速的逐日均方根误差总体小于日最大风速,且更为稳定。对比相似成员集合性能,日平均风速各成员也比日最大风速表现更为稳定且集中,同时两者集合离散度和集合平均均方根误差较为接近,表明两者都有较高的可信度。

Using the reanalysis data of ERA5 and observations from conventional stations and the method of analogue ensemble,this work makes corrections to applicable diurnal mean and maximum wind speeds(to be referred to as the“D-mean wind”and“D-max.wind”respectively hereafter)for the surface level in the western part of Guangdong province.The results are shown as follows.With the corrections,the accuracy of both the D-mean wind and D-max.wind is much increased,with substantial improvement even for mountainous areas with complex terrain.Day-to-day root mean square errors of the D-mean wind are generally smaller and steadier than those of the D-max.wind.For the ensemble performance of analogue members,individual members for the D-mean wind are more stable and more concentrated than those of the D-max.wind.On the other hand,the ensemble discrete and the root mean square error of ensemble average are quite close between both winds,suggesting high reliability.